Managing algae III

Things quickly went from bad to worse.

I coupled a water change with manual removal of a large amount of various kinds of algae. I dug through my collection of 'aquarium stuff' and found an (old) bottle of Seachem Flourish. Great; although it's not marketed as an algaecide, it often works. So I added some. Then I realised that what I had wasn't Flourish Excel, and rather than adding a carbon source, I was adding fertiliser. Not what I was thinking, but it should still boost plant growth, and hopefully would help them compete with the algae.

Already on Friday (the day I did the water change) I noticed that they water wasn't terribly clear; by Saturday it was noticeably more cloudy. The algae on the driftwood was also growing like crazy, and I removed a lot more of it. Saturday evening I visited the pet store in search of Flourish Excel and found instead API CO₂ Boost. Since it's basically the same stuff (glutaraldehyde) I decided to buy a bottle and see how it would work. I added my first dose that night.

By Sunday, it was obvious that something was wrong. I had a growing green water problem (overgrown of unicellular green algae). Over the next few days I kept dosing with the CO₂ Boost, and the water kept getting greener and greener.

By Tuesday afternoon the water was very green and cloudy.

On Thursday it was bad enough that I decided to stop the experiment and do a major water change.

Wednesday, 11:40 am

Wednesday, 4:14 pm

Thursday, 11:58 am

As I started to refill the tank I added dechlorinator to the water I was about to add, together with the  CO₂ Boost and, without thinking, the fertiliser. Then it occurred to me to wonder what was in it. A quick glance at the bottle clued me in to the likely cause of my green water problem - the first listed nutrients were N and P. Just what you don't want in a tank with a green water problem. At that point I realised I had a problem.

After the water change, things looked a lot better, but the water was still green (upper image). Less than an hour later, the water was noticeably greener.

Normally, the best course of action is to fix the problems with the water, but in this case it didn't seem like the most viable solution. I had elevated the levels of phosphate. It would probably have taken several water changes to get it back to something like the baseline level.I decided, instead, to dig out UV Steriliser. A UV steriliser uses ultraviolet light to kill microorganisms in the water. I bought it many years ago to fight ich (quite successfully) and hadn't used it in years.

Within a few hours, there was a visible improvement in clarity.

Two hours later, further change was visible.

The following afternoon, things have improved even more.

Afternoon of day two, and the water clarity is better than it even was.

By the morning of the second day (Saturday) the water was pretty much clear. Saturday afternoon, 48 hours after I started running the UV steriliser, and the water clarity is as good as it have ever been in this tank. I'm really impressed with how quickly it managed to get the job done. Granted, a 24 W unit is overpowered for a 55 gallon tank. But it did the job remarkably quickly.

Ghost shrimp

The latest addition to my tank is a small group of Ghost shrimp (Palaemonetes sp.). I like the idea of having shrimp in my community tanks, and Ghost shrimp are both large enough to coexist with the fish I have, and cheap enough that I can afford to keep them in conditions where successful recruitment of offspring is unlikely.

Fish are most interesting if they're are active swimmers. The appeal of shrimp, on the other hand, lies in the fact that they don't move much. They tend to spend much of their time in one spot, feeding on whatever detritus or algae is at hand. Being translucent, Ghost shrimp may not be the ideal aquarium shrimp, but they make up for this limitation by being cheap enough to stock at relatively high densities. They also happen to be large enough to coexist with the fish I have in my community tank - Glowlight tetras, imperfectly identified Blood tetras, two species of Corydoras, some Otocinclus and several kuhli loaches.

I decided to use my algae issues as an excuse to add a few Ghost shrimp to my tank. After all, there tends to be a relationship between species diversity and stability in ecological systems. I can't say it helped (I would honestly be very surprised if eight shrimp - or fewer - could make any change in a 55-gallon aquarium, especially given less than a week to work at it). Not to mention that they are supposed to feed primarily on algae.

After a week there are between five and seven survivors. I found one shrimp dead the morning after I purchased them (the smallest of the group); I'm hoping the rest of them made it. I saw five of them together yesterday - that sets the lower limit on the number of survivors - but generally I only see two or three of them at a time.

Palaemonetes paludosus, the eastern Grass Shrimp.
Public domain image. Original image by Joseph Stansbury Rosin, cropped and sharpened by Kazvorpal.

The Ghost shrimp available in pet stores in the US appears to be Palaemontest paludosus, the eastern or riverine Grass shrimp. One of the most interesting things about these shrimp are that they apparently dig quite extensive burrows. Via The Aquarium Wiki

The Ghost Shrimp burrows to feed and digs its two to three foot deep burrow with the claws of the first and second legs. It uses these legs to draw the sandy mud backward and collect it in a receptacle formed by another pair of legs. When the receptacle is full, the shrimp crawls backward, reverses itself in a special turn around chamber and then deposits its load outside. The burrows are not permanent. A number of branches and turnaround chambers are found in the burrows and they have at least two openings to the surface. The shrimp use their pleopods to produce some circulation of sea water through the burrows. The pencil-sized openings of the burrows are typically in the middle of little piles of sand or sand with small pebbles.

This would suggest that tanks with coarse gravel bottoms may not be ideal for keeping these shrimp. It might also explain why I rarely see more than one or two of them at a time. It does seem hard for me to envision how such a small shrimp would build and maintain such an extensive system of burrows.

Female carrying eggs. Public domain image courtesy Vlad at The Aquarium Wiki.

Observations on Blood tetra behaviour II

Some further observation on the Blood tetras.

[Update: These may not be Serpae tetras, so I'm referring to them by the broader term, 'Blood tetras']

One of the obvious questions about these interactions between the "Serpaes" is the question of what's aggression and what's mating behaviour. Several days ago I noticed a few of them and a few Glowlights hanging around the top of my (small) clump of Cambomba. From what I have read of breeding Serpaes, it seems that fine-leaved plants (like Cabomba, presumably) are attractive sites for Serpaes to spawn (and presumably other Blood tetras). It makes me wonder whether these fish were feasting on freshly laid eggs (though, of course, if they were, it might have been Glowlight eggs as well).

Serpae tetra? Or not?

One of the things I noticed about my Serpae tetras (or 'Red minor tetras' as they were labelled in the pet store) was that only one of them had the characteristic black 'comma' mark behind the operculum (i.e., the gills). That one individual was also significantly redder than the other fish.

I visited the same store today and noticed that in addition to their 'Red minor tetras' they also had a tank of 'White-finned rosy tetras' (Hyphessobrycon bentosi), and that these fish matched what I had. So, I wondered, were my original fish mislabelled? And what were these fish?

First problem was that name: white-finned rosy tetras. Google around and you find 'Rosy tetras' (Hyphessobrycon rosaceus) which look a fair bit like these fish, and 'Ornate tetras' (Hyphessobrycon bentosi). So do I give Petsmart the benefit of the doubt and trust their ID of H. bentosi (though it's noteworthy that their website, unlike the store, doesn't appear to attach a species name at all to the 'White-finned rosy tetras') or should I follow the more common result on Google and assume that they're H. rosaceus?

Unsure how to proceed, I decided to get a sense of the genus Hyphessobrycon. The Wikipedia article on the genus notes that there are over 100 species (as of 2005), but only a handful of these have Wikipedia articles. That said, the coverage of commonly kept aquarium fish is pretty decent, so I decided to see how well I could match my fish with those covered.

Some of them were easy to dismiss as candidate species. Hyphessobrycon columbianus, the Colombian tetra, is described as being silver-grey in colour with a turquoise tinge from the lateral line upward. Several others were also easy to dismiss: H. herbertaxelrodi (the Black neon tetra), H. heterorhabdus (the [Belgian] Flag tetra), H. megalopterus (the Black phantom tetra) H. anisitsi (the Buenos Aires tetra) and H. pulchripinnis (the Lemon tetra) are all easy to rule out; they look nothing like these fish. But that still leaves quite a few candidates (among the species with Wikipedia articles) that required closer examination.

The Black neon tetra, H. herbertaxelrodi, is clearly distinct in both colour and body shape from these tetras.
Photo copyright Juan R. Lascorz, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Ruling these species out was the easy part. Identifying a good candidate among the remaining species was a little more difficult. Hyphessobrycon amandae (the Ember tetra) appears to have a narrower body and smaller fins. The Flame tetra (Hyphessobrycon flammeus) has the right body shape, but has a pair of vertical bars. My fish also lack the prominent red spot associated with the Bleeding heart tetra (H. erythrostigma). This left five reasonable candidates: H. bentosi, H. eques, H. minor, H. rosaceus and H. sweglesi. These five deserved more careful examination.

My fish (Hyphessobrycon sp.)

My fish are orange-red tetras with a relatively thick body. The dorsal fins are back with white edging; the forward third of the dorsal fins are also white or red. Only one of them has the red 'comma' mark typical of Serpae tetras (though apparently not invariably present.

Note the black dorsal fin edged with white. The front end of the dorsal fin can also be white or red. The anal fins are also white-edged, with a black dot at the rear edge (not visible here). Also not visible are the white edges on the pelvic fins.

Same group of fish. Note the black spot at the distal end of the anal fin (clearly visible in the top fish).

Hyphessobrycon eques (Serpae tetra)

This was, after all, my first guess. The best argument against my fish being Serpaes is the fact that one of them clearly is, and he looks different from everyone else.

The black line behind the gills is clearly visible, as is the more intense red. Photo courtesy MiguelCampos, released into the public domain.

Hyphessobrycon minor (Minor tetra)

Given that these fish were labelled 'Red minor tetras' in the pet store, you'd think that 'Minor tetras' would be a very good guess for the identity of these fish. The problem is that this week, in addition to the 'White-finned rosy tetras' they also had a tank of 'Red minor tetras'. And in fact, these appeared to be Serpaes. That said, of course, assuming that the following image is correctly identified, it would be easy to confuse the two.

Copyright Yuriy Kvach, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Finding anything about these fish via Google is nearly impossible, since searches for 'Minor tetra' is going to be subsumed into searches for 'Red minor tetra'. The main distinguishing factor I can find is size, and since these fish are not fully grown, it isn't the most helpful.

Hyphessobrycon sweglesi (Red phantom tetra)

Another fish that looks very like a Serpae tetra, but this time with an even bigger spot behind the gills.

Courtesy Tsunamicarlos; released into the public domain.

Hyphessobrycon bentosi (Ornate tetra)

The tank I saw today at Petsmart was labelled 'White-finned rosy tetras' (Hyphessobrycon bentosi). They looked a lot like the fish I bought, but that doesn't mean they are the same.

Hyphessobrycon bentosi, Copyright Euripides, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Copyright H. Krisp, licensed under the Creative Commons Attribution 3.0 Unported license.

Assuming that these pictures are correctly identified, the most notable difference (other than the body colour, which can wash out in stressed fish) is the lack of a black spot at the far end of the anal fin. Animal-World has the following to say about distinguishing these tetras from H. rosaceus (the Rosy tetra).

These two tetras are so similar in appearance that this fish is commonly known as the False Rosy Tetra. Both have a pink to deep salmon colored body, though this species is a bit more transparent. They also each have darker red markings on their fins. They differ in that the Ornate Tetra always has white tipped fins while the Rosy may or may not, and the Rosy has a black marking or 'flag' on its dorsal fin. Other common names this tetra is known by include White Tip Tetra, White Fin Ornate Tetra, and Bentos Tetra.

Not entirely useful, but it does suggest that the paler colour of these fish may not be incidental.

Hyphessobrycon rosaceus (Rosy tetra)

This brings us to our final candidate, the Rosy tetra. After all, the fish today were labelled as 'White-finned rosy tetras'.

Copyright Aquakeeper14, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Problems begin with the descriptions of the species. From Wikipedia

The rosy tetra has a light pink-white body with red fins, except the dorsal fin which can be black or white, and the caudal fin which is pink-white with two elliptical red spots on it. It has a faint black line from the top of its eyeball through the pupil, to the bottom of the eyeball. 

Animal-World has this to add

The Rosy Tetra Hyphessobrycon rosaceus is a fun addition to a peaceful community aquarium with other smaller fishes. It has the deep bodied shape of the larger tetras like the Bleeding Heart Tetra. It is also quite pretty with its deep salmon body color highlighted with red accents and bright white tips on the fins. 

Conclusions?

So what do I have? I don't know. Only the Serpae tetras and the Minor tetras had the black spot on their anal fin in any of the pictures, but sadly none of the species descriptions matched them at all. All I know right now is that I have some sort of Blood tetras. Beyond that, I'm still uncertain.

Observations on Serpae tetra behaviour

As I mentioned previously, I recently acquired a school of Serpae tetras. And they weren't quite what I expected (though the fault was mine for not doing better research). So a couple weeks on, what do I think of them?

[Update: These may not be Serpae tetras.]

To their credit, they're attractive, active fish. They use the entire water column (at least with the tank-mates they currently have) but seem to favour the front of the tank. (Again, that might be specific to these fish, but they certainly are aware of humans and know that we're a source of food).

They are strongly motivated by food. My Glowlight tetras have limited interest in a block of dried tubifex (they will eat the floaters dislodged by other fish, but they won't attack the block itself) and almost none in algae wafers. The Serpaes, on the other hand, will greedily attack dried tubifex and sinking algae wafers. While the Glowlights will spit out flakes that are too large for them, the Serpaes hold onto any food and eventually swallow down whatever they get a grasp on (often looking like they're at risk of choking on the food, though I suppose that in order to choke you need lungs).

As tetras go, they're fairly aggressive. While most of the aggression is directed at conspecifics, they Serpaes seem to have effectively banished both the Corys and the Glowlights from their preferred terrain (the front of the tank) except when food is present, when they seem to focus their aggression on conspecifics. The intraspecific aggression is interesting - one fish will go at another with its dorsal and anal fins expanded. Sometimes the fish that's attacked will swim off (in which case the aggressor seems to give chase) while other times they will spin around and stand their ground, responding with a similar display. The two combatants may clash a couple times before one retreats, though rarely very far. This sort of thing usually happens around food, especially algae wafers.

Tubifex blocks are very light, very low density - they're just freeze-dried worms compressed into a block. Once they fish start to attack them, they are quickly dismembered (especially if the fish in question are Serpaes or Kuhli loaches...Corys, which don't actually bite into things, can't break the block up as quickly). Once the Serpaes get to them, they don't last very long. Algae wafers, on the other hand, as fairly solid, although they gradually soften up as they soak in water. Since they last longer, they are soon covered with a scrum of Corys which completely cover the block and only offer armoured tails to the Serpaes. As a result, the Serpaes gather around above the wafer, waiting for the wafer to be exposed (which happens every now and then as the Corys move the wafer around and flip it over, and every so often seem to lose the wafer entirely). It is at this time, when the Serpaes are gathered together for a prolonged period, without clear access to the food, that I observe most aggression.

I hope that as the plants grow the sight-lines in the aquarium will be more broken up and life will become more peaceful.

Managing algae II

The following combination is a great recipe for an algae outbreak: a relatively new tank, fairly high fish stocking, new lights and a long photoperiod. And that would be where I find myself.

My driftwood has always supported a large population of Cladophora. It had vanished while the log was dry, and didn't show up in the new aquarium until I replaced the lighting. I'm not sure whether this reflects a lag time in growth (from spores or resistant bits) or whether it was simply a response to the higher light. (Obviously the high light helped it grow, and grow it did, like crazy). While many aquarists consider Cladophora to be the bane of their existence, I'm actually fond of it, as long as it stays on that piece of wood. It does require regular removal, but given its coarse texture, it is actually quite easy to remove.

If Cladophora had been the only issue, I wouldn't have been bothered. I also managed to attract a population of what some call 'green dust algae' - fine stuff that covered the glass. Initially I took it for green water (which is a problem) but then I realised it was just on the glass. It's easy to scrape, but right now it's growing like crazy. My problem is that I also have at least two other types of algae, and these are a bit problematic. I have some blue-green algae forming in a couple places. I don't care about it on rocks, but it is also growing on my plants. That's a problem, that I will need to sort out one way or another (it's not an easy problem to solve). Then I have something that's new to me. It fits the description of 'green hair algae' (and possibly some 'thread algae' on my filter outflow). Not good stuff to have around. For starters, it seems to grow like crazy and attach to anything (plants, heater; it's even smothering the Cladophora). It's also very slimy and insubstantial - people recommend twisting it around a toothbrush to remove it). 

More on Serpae tetras

After observing them for a week in my main tank, I can report that Serpae tetras may not be quite what I expected them to be.

[Update: These may not be Serpae tetras.]

I have kept a number of tetras over the years (neons, cardinals, rummynose, glowlights) and I have always found them to be exceptionally well suited to a community aquarium - they are peaceful, attractive fish that bring life and colour to the mid-waters of the tank. While they are strikingly pretty fish which bring life to a tank, my Serpae tetras are far less peaceful than the other tetras I've kept.

For starters, they are aggressive feeders. While glowlights will spit out food that's too big for them (and maybe take a second or third bite at it), the Serpae tetras would not let go of a piece of food once they had a bite of it. They also go after food quite aggressively, even challenging the (must larger) Corydoras and kuhli loaches. Again, unlike the glowlights, which rarely go after food on the bottom of the tank, the Serpae tetras will go in for it.

They are also much more aggressive tetra-to-tetra. They will bully the glowlights just a little, but far more noticeable are the occasional clashes with their conspecifics. Just a few of the largest fish fight with one-another, but as they settle in, these clashes seem more common. I doubt schooling tetras are likely to be territorial, so presumably this has more to do with setting up a dominance hierarchy.

Planting dwarf hairgrass

As part of my aquarium re-do I decided to add some dwarf hairgrass (Eleocharis parvula) to the foreground. The plants I bought formed a dense mat of runners that I separated into a number of large clumps that I anchored with half a toothpick. While the clumps stayed put pretty well (although foraging corys uprooted a couple of them) I was left with a lot of smaller bits floating on top of my tank. While it was only a small portion of what I had bought, it was still a lot of plants, and it seemed wasteful to discard them (or really, just let them float until they were battered to death by the water flow).

Having done the planting I found myself wondering how I should have done it. I looked around online and found this video.

It looked like an interesting, albeit labour intensive, way of getting things planted, so I tried it with my leftover floating bits of the plant.

As I thought, it's tedious and labour intensive. I gave up after a dozen or so plantings. It was also a very effective way of getting the plants rooted - something I wish I had learned years ago. I tried it with a fragment of Ludwigia that had floated in the tank for the last two weeks (and grown a long root). It worked just as well. While I'm a little concerned that I might be burying the stems a bit too deep in the substrate (though, luckily, it's just gravel) I'm not too worried. I'll see how things work. So far though, it seems like a good technique for planting any small aquarium plants, especially those that come as cut stems with no real root mass. (I wouldn't, for example, try that technique with a sword.)

Serpae tetras

Hyphessobrycon eques. Photo by Alexander Dubrovsky, released into the public domain.

The local big box fish store happened to have a big sale recently; among the various discounted fish was a tankful of what they called 'minor red tetras'. This name was new to me, so I looked it up and it turned out to be one of the many names for Hyphessobrycon eques, more commonly known as the Serpae tetra. On a whim (and since there was space in my newly renovated tank) I decided to buy what they had.

[Update: These may not be Serpae tetras.]

Although the fish I keep are generally South American, I have barely scratched the surface when it comes to tetra diversity. Mostly I've seen the long-finned variety in pet stores, and they always struck me as slightly sad, slightly clumsy-looking fish. These guys though are attractive little fish, fairly active in the mid and upper water of the tank, willing to school near (or even with) my Glowlight tetras.

I can't speak for them in the long term, but thus far, I'm happy with the addition.

Crypt melt

Within a few days of re-establishing my main aquarium, I noticed that my Crypts (Cryptocoryne wendtii, as far as I can tell) were not looking to well. With the move and everything, I didn't give it a whole lot of thought - most of the plants were looking more than a little worse for wear.

Nice growth of Crypts - obviously not mine!

Cryptocoryne wendtii, from Wikimedia Commons. Copyright User:Haplochromis. Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license

Over the next week the leaves, already flopped over, grew thinner and less substantial and it was apparent that this was the thing I had long read about, but never actually seen - Crypt melt. Eventually nothing was left but a few petioles and a mass of gunk clogging the intake of my filter. Fortunately, the damage does not appear to be permanent (except in terms of shed leaf tissue). Just a few days after 'peak melt', fresh leaves are popping up and they look healthy.

This is consistent with what I've read online. Crypts can be sensitive to changing environmental conditions, and respond by losing their leaves. Hardier species like C. wendtii do this more rarely and recover more quickly. Other species are more sensitive.

Moving, part II

As I mentioned in my last post, I moved a long-established tank at the end of July. At the new place, I housed my fish and plants in a 27-gallon tank temporarily until I had time to set up my 55-gallon tank properly. That ended up being a 3-week hiatus, while my driftwood and gravel sat outside on the back porch. Last weekend, I was finally able to set things up. It was an experience worth writing about.

The first challenge of the set-up was cleaning my gravel. In a planted tank, vacuuming the gravel is impractical, so the tank probably contained about 7 years of organic matter. Securely buried, that probably created a nice anaerobic layer where denitrification might have been occurring. Dig it up and you have a house that smells of rotten eggs. I thought a few weeks in the sun might help things, but in reality the gravel was still quite wet. And very smelly. Washing all that gravel took me about half a day, and in the end I did a less than perfect job. To be honest, I wasn't entirely sure I wanted perfectly clean gravel - organic matter in the substrate not only provides nutrients for the plants, it also provides a small amount of carbon dioxide (which can be a plus for photosynthesis).

Gravel in, I got to work on the decor. Fairly simple - some slate and a large piece of driftwood. The the plants. Most people recommend doing the planting before you add water, and I found that works pretty well; if nothing else, it lets you did holes to plant without raising debris (the gravel was cleaner, not clean). My budget wasn't that large, so I didn't buy a lot of new plants, but I was hoping what I had (and what I bought) might spread out as things progressed. Then it came time to fill it. I usually use a plate in the bottom of the aquarium to break the stream of water, so as not to disturb the sediment too much, but lacking enough open space for a plate, I used a small bowl. It worked great. While a plate dissipates the energy of the water stream, the water still flows out over the sides with some force. Using a small bowl prevented this.

Now - the problems. Leaving a large piece of driftwood out in the sun for three weeks is a bad idea. As I finished filling the tank, it started to float. I ended up lowering the water level a little so that it wasn't buoyant enough to leave the ground. After almost a week I slowly topped off the tank, and things looked fine. Until today when I had to reattach some plants that had floated up and bumped into the driftwood. To my surprise, I noticed that although the wood is resting on the bottom of the tank, it's still fairly buoyant. Hopefully it will be completely waterlogged in a short while.

Moving with aquarium fish

I always knew it was coming. I never expected to stay in that apartment - in fact, I stayed there much longer than I ever anticipated doing so. Last week I was finally forced to confront the problem of moving with fish.

As far as moves go, this one was relatively simple. We didn't move across the country - we didn't even move across town. We just moved a block down the road. We also had the opportunity to stretch the move over a few days, which made relocating the fish even easier. The down side was that I was moving a 55-gallon planted tank with substrate that hadn't been disturbed in about five years. This meant that I had thick, highly anaerobic substrate to move.

Step one was setting up a destination tank to temporarily house the fish in my new place. For this I used a 27-gallon tank without substrate. I set this up as soon as we got access to the new place. In a case like that, it's impossible to cycle a tank, but using an established filter and filling it with plants should help to alleviate that problem. I also made sure that it was very well-lit - plants that are growing are able to make use of a lot more nitrogenous waste products (ammonia, nitrites or nitrates) if they are growing. I could also have added gravel and decorations from the old tank (since they should support a healthy biofilm) but I chose not to.

The biggest challenge was emptying the old tank. The plants, rocks and driftwood were easy enough to remove, but doing so disturbed the substrate and re-suspended a lot of muck, making it difficult to see the fish I was trying to catch. Catching most of the fish was fairly straight-forward - wait for them to rest near the front of the tank and then catch them (using two nets, of course). Since they were only travelling a short distance, I placed them in a small plastic tub which I floated in the tank. I filled the tub with plants to provide cover for the fish. I floated the tub to avoid the problem of panicked fish jumping out of it - if they jumped, they would have been back in the aquarium, not flopping around on the carpet (or worse yet, cat-treats). The plant cover also should have reduced stress (and the urge to jump).

After catching what I could, I gradually lowered the water level, catching more fish as the water depth fell. The most challenging fish to catch were the kuhli loaches, which are both fast-moving and very shy. Once the fish were out, I piled the substrate to the back of the tank and scooped it out, trying my best to minimise the amount of water I was taking with me (since water adds weight to the already heavy gravel). This process also made it easier to scoop out the remaining water. Only when all of the gravel and almost all of the water was removed from the tank did I finally move the tank.

When you're move a tank, make sure you empty it as completely as possible. Aquaria are designed to handle a lot of weight (several hundred pounds)

Conclusions

1. Plan your move. This whole process would have been a lot more complicated if we had completed the move in a single day.
2. Gravel (and other substrate) is heavy dry and even heavier wet. If you can remove it long enough in advance before the move and let it dry out completely, all the better.
3. Rationalise things. Do you need all your tanks? Are there fish that you can give away to friends or sell back to pet stores? Do you have old equipment you are not longer using? Think through what you need to move.
4. Make a plan for how you're going to move your fish and plants. A short move is possible in a small tub, but a cross-country move, one that might take several days, is another matter entirely. How are you transporting your fish? Will they have enough air for the move? Are you mixing potentially incompatible fish? (Fish that can coexist in a tank with plenty of space may not be able to coexist in a small container.) What is the temperature going to be like where the fish are? Are you going to be able to house your fish when you get to your destination?

Marine aquaria and reef communities

New York Times has an article that looks at the effect of the growing popularity of marine aquaria on reef invertebrates. Unlike the freshwater aquarium trade, where captive-bred organisms dominate, the marine aquarium trade depends heavily on wild-caught fish and - more importantly, it would appear from this article - wild-caught inverts, which are important for maintaining the reef ecosystem. Since they play similar roles in nature as they do in the tank, overharvesting could have profound impacts on reef communities.

Hybrid corys?

While I've heard reports of putative Corydoras hybrids, I have never seen any direct evidence of interspecific mating until this past week.

My main tank has a variety of corys - Corydoras panda, C. punctatus, C. arcuatus, C. aeneus, a probable C. trilineatus and another species whose identity I don't know. While I started off with several C. trilineatus, I only have one left. And apparently it's a female.

A few days ago, in a rainy week, one day after doing a water change, I noticed the trilineatus in the t-position that corys adopt while mating - with a panda. She then swam off grasping at least one egg (probably more) between her ventral fins.

While they clearly mated, I have no idea if the eggs would have been fertile. Regardless, I would be very surprised to find any fry. When she tried to place an egg, the rummynoses realised what she was doing, and proceeded to chase her around, hoping for some more eggs, I presume. Even though I tried to distract them by feeding them, the odds of eggs remaining unfound in that tank are probably pretty slim

Ich update

It's been 10 days since my last post. I have long since reduced the temperature to normal and turned off the UV sterilisers. There's no evidence of ich on any of the fish. I'm inclined to think that the treatment worked.

One problem with this approach, I suppose, is that it permits the parasite to persist in the system. Fish that have recovered from ich acquire some degree of resistance. Reducing the temperature also slows the growth of the parasite. In combination this means that any residual infection would probably be difficult to detect. Ugh. Ironically, the best way to detect the parasite would be to introduce stressed fish that have not been exposed to ich. Unfortunately, that would equate to new fish from the pet store. And, in that case, there would be no way to determine whether they brought the infection with them, or whether they picked it up in my tank. I suppose the best thing to do is to observe the group of baby guppies that were born about a week ago. Not that guppies seem to be terribly susceptible...

Fighting ich

There are three places to buy freshwater aquarium fish in this town - Petsmart, Petco, and a local fish store. The LFS has friendly people and a much wider selection of fish. Unfortunately, they don't seem to quarantine their fish very well. I've had three ich outbreaks, and I believe that all of them have come from that store. Now, obvioulsy, I should have learned my lesson and made sure I quarantine all my new purchases. And for the most part, I've learned that lesson.

I recently bought a group of Otocinclus for my main tank. Many people consider them delicate fish which are hard to keep alive. My experience has been just the opposite - they strike me as almost bulletproof, great survivors. From what I've read, the main 'danger' period is just when they are introduced, because they are often very stressed in transit. Bearing that in mind, I decided to add them directly to my main tank. They seem to have settled in very nicely.

More recently I bought a group of fish from the LFS - corys, rummynose tetras, and three kuhli loaches. Given the difficulty in catching and moving kuhli loaches, I decided to take the chance and introduce them directly into my main tank. And the fun ensued.

Within a few days there were white spots on the rummynoses. I had successfully eradicated ich with salt and heat in the past, but the salt took a toll of some of my plants. I decided to try something different - a UV steriliser. When I went to the petstore, they were out of the 9V one I had my eye on, but they still had the 24V model. Now 9V sterilisers are recommended for tanks up to about 50 gallons (mine is 55), while 24V models are for tanks up to about 125 gallons. Wasn't too worried, since more power is probably better than less when trying something experimental. After I bought it, I poked around the web to see what people said about that approach. While people liked it for saltwater ich, there was a good deal of skepticism about its effectiveness for freshwater systems.

The next morning I looked at my fish and noticed that a lot of them had ich, far more than two days prior. I decided to play it safe and up the temperature. Then I hit the scientific literature.

Hitting the literature is often frustrating as an aquarist, since few papers are published on tropical aquarium fish. Fortunately, ich is a major problem for commercial aquaculturists. More so, in fact, in temperate than tropical conditions. From what I read, I realised that (a) a UV steriliser would probably do that job, and (b) heat alone would probably work as well.

Within two days of turning up the heat (three days of adding the UV steriliser) my fish were spot-free. It may be too early to say with certainty, but I feel pretty confident that it worked. And worked very well.

Kribs

Six weeks ago I purchased a pair of albino Kribs (Pelvicachromis pulcher) - I've always wanted dwarf cichlids, and the new tank was in need of occupants that could handle "semi-aggressive" tankmates. (To be honest, while Macropodus are often described that way, mine have always been extremely gentle, inoffensive fish.)

Within a week the kribs started excavating a hole below a piece of driftwood. The female then started spending a lot of time beneath the driftwood. Cool, I thought, they are interested in mating. The second week passed, and the female spent a lot of time out of site. I didn't give it too much thought. Then at the start of week three I came home one day to notice both kribs were out on the open, keeping close to the bottom of the tank. As I looked a little closer I noticed movement beneath them and realised that they hadn't "considered" spawning, they had gone ahead and done so. Given that there were four large Macropodus in the tank with the kribs, I immediately became concerned for the safety of the fry. The kribs seemed to be attentive parents and the Macropdus had little interest in what went on at the bottom of the tank, but it still seemed only a matter of time until the krib fry turned into Macropodus snacks. It was thus quite a surprise when I realised that the kribs were quite effectively bullying fish that were 2-3 times their size. Even the (rather small) female krib was able to chase the Macropodus males off when they ventured too far down the water column.

Over the past three weeks the fry have grown remarkably quickly. Initially they foraged in a tight bunch on the bottom of the aquarium, attentively guarded by one parent (while the other parent patrolled the tank). As they got bigger they started moving away from the bottom, higher up the water column. On at least one occasion the parents seemed unsure what to do when half of the babies were on top of a piece of driftwood while the other half were foraging nearby on the bottom of the tank. Over the last week the fry have spread out and no longer forage as a group. They have also reached a size where they are no longer at much risk from the Macropodus - one of the fry ended up high enough in the water column that it attracted attention from one of the female Macropodus. She swam over to check it out, but then turned away. I'm guessing it was too big for her to consider it food.

Now what do I do with 20 kribs?

Stocking

At some point, every aquarist has ask the question "how many fish should I put in my aquarium?" Conventional wisdom says "one inch of fish per gallon". Earlier this year I blogged about two articles that challenged that dogma, one in Practical Fishkeeping and the other in Tropical Fish Hobbyist. In each case, they suggested that a well-established tank could support twice that level - two inches of fish per gallon.

While territoriality and aggression can play into the number of fish you can keep in a tank, those are species specific considerations that overly any basic rule of thumb. Far more basic is the issue of oxygen supply. While certain fish depend on gaseous oxygen (the best known being the anabantoids), most fish depend on dissolved oxygen. Too many fish and too little surface area will lead to problems. The other issue is "bioload" - the production of waste products by the fish. These include nitrogenous compounds and organic waste. Ammonia and nitrites are harmful at relatively low concentrations; they tend to be a problem in new tanks, but can also build up in established tanks if the biofiltration crashes. Chances are though, if the biofilter crashes, even a moderately stocked tank will run into major problems. Nitrates, on the other hand, are only a problem at higher concentrations, but unlike ammonia and nitrites, they are not broken down by most biofilters. Organics are a separate issue - one that doesn't seem to get all that much attention. Some people specifically add organics ("black water extract") to their tanks. Others stress the importance of water changes to control the levels of organics. The simple truth is that there are a whole host of organic compounds, and their effects on fish are going to vary.

Bearing all this in mind, and the fact that "inches per gallon" is a very crude rule of thumb (more on that later), I sat down and assessed stocking in my main tank this morning. It was an interesting exercise - based on the "inch per gallon" rule, my tank is slightly overstocked. Of course, that involves weighing a 3.5-inch kuhli loach as placing a greater demand on the system than a 3-inch Macropodus (which probably has more than twice the body mass, but almost no dissolved oxygen demand). If I chose to follow the "two inches per gallon" rule, I could almost double the stock of fish in my tank. Right now, that seems reasonable - the upper two thirds of the tanke are currently occupied by three fish; everyone else is near the bottom of the tank (and largely hidden by the plants). Things looked different this morning just after I fed the fish - in the flurry of activity, the tank seemed to have twice as many fish as it does now.

Aside from the obvious issues of filtration and water changes, I think there are two main things to think about when it comes to stocking - the space available, and the overall ecology of the tank. The main tank tends to have higher nitrate levels than either of the small tanks. This is largely a function of the amount of plant biomass - the other tanks are choked with plants, which presumably consume any available nitrogen. The main tank, on the other hand, has far less plant biomass (though this may change). Increasing the plant biomass probably increases the overall number of fish the tank can support. The other issue is one of space. Where in the water column does a fish live? Recommendations for cory stocking seem to be expressed in terms of tank surface area - or actually, the area of the base of the tank. (Is this modified by having a more heterogeneous tank bottom?) In my main tank, the open water is only used by the Macropodus. The corys spend their time on the bottom of the tank, with occasional forays up and down the plants. The Glowlight tetras tend to swim among the plants, while the Rummynose like the open water in front of the plants - they rarely venture above the level of the taller plants. (I suspect that as the plants get taller, they will expand their usage). So in terms of fish to add, the obvious choice would be an open-water species (zebra danios are what come to mind) or a surface species (guppies or some other small live bearer?) That is, of course, if I decided to trust the two-inches-per-gallon rule of thumb...

Tank talk and lighting options

As often happens, I went through a period of neglecting my tanks, especially my (55-gallon) main tank. It's the kind of thing that happens to almost every aquarist at some point in time. The main tank has always been light-deficient - while most people recommend 2-3 watts per gallon* for a planted tank, my plants were forced to get by with approximately 0.55 watts per gallon. As long as I was feeding them Flourish Excel, the plants seemed happy (especially the Cambomba), but once I quit, only the Java fern and Echinodorus ("Amazon swords") did much.

While the main tank was suffering a lack of plant growth (somewhat masked by the expanding Java ferns), my other tanks were experiencing the opposite problem - too much plant growth. The plant tank was covered by an emergent carpet of Ludwigia and Bacopa monnieri; the tank itself had turned into a mass of roots. The Otocinclus tank was similarly overgrown, although instead of being covered by emergents, it was covered by a think layer of floating plants.

At the end of July I shook myself out of my torpor and started moving plants from the plant tank to the main tank. I realised that I had to upgrade my lighting, but at that point in time, it just wasn't an option. I replanted a lot of Ludwigia and a little Bacopa into the main tank, and cleaned up the mass of floating vegetation (I either replanted the stuff, or got rid of it). And then I had to leave it all alone for a week and a half.

One of the main reasons I wanted to clean out the plant tank was the fact that we would be gone for a while. I don't have a timer on that tank, so I have just left the lights on when we are gone. One time I returned to find the tank a thick mass of hair algae - so thick, in fact, that the water was obviously not circulating (some areas were very warm, others were far too cold). While that is likely to be less of a problem in summer, I still wanted to clear out enough vegetation to give it some room to grow. But moving plants to the main tank created a problem - did I really want to go to all that effort, and then watch the plants turn into spindly things before slowly dying? While a lighting upgrade was in order, I had neither the time nor the money for anything of the sort.

On the way home from Michigan I finally stopped into Preuss Pets in Lansing, Michigan. A friend of mine has been saying great things about them for years, all the more now that they have moved to a larger place (more later). I ended up buying a really nice new lighting system, and I now have two 54 watt bulbs on the tank. Not too surprisingly, the change was remarkable. I have also continued to move plants from the plant tank to the main tank. It's too early to say home much of it will really take (a lot of what I transplanted was emergent in the old tank, so it will have to adapt to being submerged), but the tank looks great and the fish seem happy, poking around in the new vegetation.

* It's actually more complicated than simply "watts per gallon" - not only does the light output matter (not all 30-watt fluorescent bulbs are the same), it also matters what wavelengths the bulbs produce.

Baby Corys?

A while ago I tried to convince my pygmy corys to breed, but without much luck. Water changes (especially in coincidence with weather fronts) could get them to come out and "dance". Recently I have noticed more complex behaviour, including what looked a bit like the "classic-T" behaviour that spawning corys adopt. But I had pretty much given up hope of anything actually happening.

Last night I noticed something moving at the front of the tank. Before it darted back into the thicket of Hemianthis I saw something that looked like a tiny tadpole, maybe 4-5 mm long. It took me a moment to realise what I had seen - fry! Over the next couple hours I caught another glimpse of it. Very cool!

Now, I can't say for certain that it actually was a baby cory - there are also a few Otocinclus in the tank, but odds are that it was a pygmy cory. Pygmy corys are considered easy to breed, while Otos are rather less easy. Also both fish are easier to breed in groups - I had 7-10 corys in the tank, but only three Otos (and one, I suspect, is a different species from the other two).