Thursday, 28 August 2014

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.

Sunday, 24 August 2014

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.

Friday, 1 August 2014

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)

  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?

Tuesday, 23 March 2010

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.

Saturday, 31 October 2009

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

Thursday, 17 September 2009

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...

Monday, 7 September 2009

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.