Hope springs eternal

Bad tank experiences can be disheartening, but I'm far from ready to give up my dreams of the perfect planted tank. We moved again last year, and my fish went into what were supposed to be "temporary" accommodations. My main tank sat empty in the garage for a while, and then sat empty in my office for a while longer.

I wanted to create raised terraces in the corners, but my previous attempts hadn't worked. If you mound the substrate to the back, it eventually levels out. If you try to keep sand behind barriers, it slides around or under them (and I'm just not ready to glue things to the base of my tank. Finally I went with a mix of substrates - coarser gravel in the back corners and a plastic mesh supported by a "wall" of small pieces of slate. I covered that with sand and...it seemed to hold up.

I added some hardscaping, a large piece of driftwood, and started filling the tank. The raised portions seemed to hold up well, but I ran into the problem of floating driftwood. The piece of driftwood I was using had sat out of the water for more than three years. Since it was much too big to attempt the usual recommendation for floating driftwood (boil it to drive out the air) my only real option was patience. So I left things alone for a few more weeks while the driftwood became waterlogged.

Finally I bought some plants, got things set up, and finally I have a tank.

I'll give the plants a while to get established before I add fish, filtration, and maybe, just maybe, a CO₂ system.

I'm hopeful things will turn out better this time. The old location seemed good, but it did have light shining through a south-facing window into a corner of the tank. That might have been a large part of my algae problem. They say that CO₂ additions tend to tip the balance in favour of vascular plants. So if I got that way, I might have fewer problems. And, I suppose, I just need to intervene more. As much as I like Java moss, it might not be the best way to go - it's impossible to get algae out of Java moss. So I'll see.

Two years later

I'm not much of a blogger any more, especially not much of a fish blogger. My last post, A blank slate, was supposed to be my story of how I created a new tank, and how wonderfully it all turned out. I'd let things grow, and I'd be able to post the kind of beautiful pictures I posted in A lack of updates.

Things didn't work out that way.

Instead, it's been two years of algae problems and no more than modest successes. Two years of disappointingly messy tanks and long periods of neglected maintenance.

A tank that goes well is a joy to behold. The plants look gorgeous, the fish set things off ever so nicely. If you fall behind on your maintenance, the robust system just takes care of itself. But a tank that never quite settles out right is an ongoing struggle. It's hard to motivate yourself when things aren't going well. Algae outbreak, mediocre plant growth, all sorts of things like that. But that's the kind of tank that needs more interventions, not less. If you don't do it, the whole system just limps along.

A blank slate

Another move and I'm back to a blank slate. Especially since I managed to kill all my abundant plant collection (probably has a far higher replacement cost than my fish, which made the trip quite well and and healthy, if unhappy, in temporary accommodations.

Lots of potential - really I'm limited only by my imagination and my budget (both of which are very real constraints). So where do I go...?

A lack of updates

Both the excitement and the frustration of aquarium-keeping tend to come within the first few months of setting up a tank. Algae outbreaks tend to be par for the course. New fish bring with them a fascinating repertoire of behaviours, but can also bring problems (disease, conflict, failure to thrive). And the plants you put so much effort into setting up and arranging just the way you want them seem to have a mind of their own. Some you hoped to fill out die or get uprooted, while other spread like weeds.

After a few months, things tend to work themselves out. The fish adapt to your tank and to their new tank-mates. The plants get established (or die) and your main concern tends to be trimming them back and working on a coherent aquascape. (There's always the challenge of filling that one troublesome spot, or that one troublesome plant, but it tends to become a minor annoyance you're happy to live with.) Algae problems never go away, but they fade into the background. All is well and you can sit back and enjoy your tank.

That's about the time you start thinking about setting up a new tank, and replaying those problems all over again.

Blackworms

I've never given my fish live food (other than brine shrimp and some inverts that somehow colonised one of my tanks) but I got my hands on a bunch of blackworms that were left over from a lab exercise. So into my tank they went and the massacre commenced.

Blackworm behaviour is interesting - in a smooth container they form a large mass of worms which coil together. When I dropped them into my tank they initially clumped together - the ones that landed on plant stems turned into a mass the reminds of a group of swarming bees which have settled on a tree trunk.

Cluster of blackworms on a Ludwigia stem. 

Once the blackworms made it to the bottom of the tank, their behaviour changed. Instead of remaining in a tight clump they spread out on the bottom of the tank with one end buried in the substrate and the other extending into the water column

In normal circumstances, this is probably a good way for the blackworms to forage while providing themselves with an escape option. From the Wikipedia article about Lumbriculus vaiegatus;

When touched, L. variegatus will attempt to escape, either by swimming in a helical ("cork-screw") fashion, or by reversing its body. The escape pattern used depends on where the worm is touched: anterior touch elicits body reversal, whereas posterior touch triggers helical swimming. L. variegatus has quick reflexes, and uses its photoreceptors to detect shadows and movement, both used to escape threats. The posterior end lifts out of the water and forms a right angle. It is then exposed to air and is used to exchange oxygen and carbon dioxide, although this exposes its posterior to its enemies. If the photoreceptors detect a shadow or movement, the posterior rapidly shortens in response to a threat.

Given the way that the blackworms positioned themselves on the bottom of the tank, it seems likely that the reversal behaviour draws the organism down into the substrate where it would be safe from predators.

Absent the corys and kuhli loaches, the blackworms which made it to the bottom of my tank would probably have been safe. While the tetras greedily attacked any floating worms (and eventually found the worms that had settled on the vegetation) the worms that made it to the bottom of the tank seems to have been safe from them. Even the large mass of worms in the second picture (above) elicited no response from the tetras (although they were eventually find the worms which had settled on the vegetation. The corys, on the other hand, were not only able to find the worms on the bottom of the tank, they also seemed to be quite successful at digging them out of the gravel (and in so doing, managed to uproot several plants). A day later there were still a few worms sticking out of the gravel where the thickest clump had been located, but I don't see any left. It's entirely likely that some - maybe even many - survived by burrowing into the substrate where they can grow and reproduce (and hopefully, continue to become cory food). But that might just be wishful thinking,

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.