Monday, 29 October 2007

Substrate in a planted tank

When I set up my tank, I was at least as interested in having plants as I was in having fish. To that end I bought a bag of nutrient-rich substrate, which is covered with a layer of pea gravel. Therein, I suppose, I made my first big mistake. While the gravel made an attractive bed for the aquarium, it isn't the best thing to grow plants in. So while you see pictures of planted tanks in which the plants spread rapidly, the coarse gravel which covers the bottom of my tank is likely to be a serious hindrance to the development of the sort of "carpet" of vegetation I would really like. Of course, there are other hindrances - lighting and carbon dioxide. While I have improved the lighting in all of my tanks, I'm sure carbon dioxide levels are still inadequate. While passive CO2 systems are easy enough to build, you really need to monitor pH if you add CO2. After all, excess amounts of CO2 could harm the fish.

In a sense I am still early in what I might consider the third stage of tank evolution. In the first stage I planted the plants I bought, and watched the fish dig them up. Then, when I salted the tank to handle my ich outbreak, I lost a lot of plants. I also kinda gave up on the whole idea. More recently, especially since I established the plant tank, I have given optimism a new shot. With the plants I established in August and September growing, and with some new plants from Houston, there's enough stuff in there to start thinking some more about aquascaping. Removing the mass of floating plants (mostly uprooted stuff) has changed the light distribution in the tank.With most light penetrating to the depths of the tank, I am hopeful that my plan to create a shorter "meadow" to the from of the tank might work. At least somewhat.
Here are a couple shots of the tank when it was first set up. The left side of the tank is still remarkably similar - the area is still dominated by the two Echinodorus plants that I put in first. While some of the Java fern (visible below the intake for the filter) are still around, I don't think anything else survives except for a tiny piece of Bacopa.
Here's the tank today:

While it's nowhere near a perfect planted tank, I think it has matured nicely.

Saturday, 27 October 2007

Betta Plant Bulbs

A few weeks ago I picked up a package of dried bulbs labelled "Betta Plant Bulbs" (Aponogeton ulvaceus). And then I put it aside and did nothing.

I finally got around to looking up what the species was like. On PlantGeek the species is described as:
A very striking plant with huge fluted and sometimes corkscrew leaves. This plant does best in a large aquarium where it will take over a large portion of the tank. It may or may not require a dormant period.
They also describe it as requiring "medium high" light, which probably means my tanks will be on the low end.

The package contained seven bulbs. I put four in my main tank, two in the plant tank and one in the Macropodus tank. While the package says "guaranteed to grow in 30 days" (or they will replace the bulb(s) that fail to grow), replacement requires that you (a) retain "proof of purchase" (did I keep the receipt?) and (b) that you return the bulb. Which would mean digging through the substrate and finding it. Since each bulb is worth about 50 cents, between postage and the disturbance to the tank, it's pretty safe to say that I won't be seeking a refund (which makes me a bad consumer).

Hopefully there'll be something to report within the next 30 days.

Thursday, 25 October 2007

Macropodus social organisation

Macropodus (Paradise fish) are supposed to be aggressive and territorial, unlikely to tolerate others of their species. Siblings are sometimes described as being more tolerant. Having started off with a pair and gradually added several of their offspring into the tank, I seemed to have the perfect Macropodus society. Aggression was minimal, and I saw no evidence of the sort of behaviour I had read about. I gave away the first batch of progeny, and had the same experience when I added some more juveniles from the breeding tank.

My second purge was more extensive, and I ended up giving away all the large Macropodus. So when I added a new batch from the breeding tank, the effect was very different. They have remained much more aggressive with one-another, displaying at (and chasing) their siblings. No clear dominance hierarchy seems to have emerged either. Since it makes for far prettier fish, and since I haven't seen any evidence of fin damage or wounding, I am not too worried - just interested in how social dynamics seem to emerge.

Wednesday, 24 October 2007

Breeding Angelfish?

Two of my four angels died in the aftermath of my neon tetra fiasco. Since I lost one member of each "pair" of angels, I figured that my chances of breeding them was pretty close to nil. However, the two surviving angels are now behaving like they intend to breed.

Over the last week or so, the angels became very aggressive with one-another. That was nothing new - when there were four fish, they fought over the tank. One pair claimed the central half of the tank, and forced the other pair to occupy the ends of the tank. But this behaviour was different - one fish would attack, but the other would stand its ground, but not fight back. More tellingly, they have taken to cleaning Echinodorus leaves. After reading Bill Dawes FAQ on breeding angels, it seems pretty likely that they are attempting to spawn.

Monday, 22 October 2007

Cherry shrimp

I have been intrigued by shrimp for a long time. Petsmart always has lots of ghost shrimp, but Lindsay has never liked transparent organisms, so I was really glad to come across Cherry shrimp in Houston. They weren't cheap, but they are supposed to breed readily. I'm hopeful - I love shrimp in aquaria.

Managing algae

The plant tank has always had an algae problem. Initially it was overrun by cyanobacteria (blue-green algae), and then it had an infestation of a brownish-looking alga. Adding some corys helped, since they disturbed the bottom and broke up the near-continuous mat. When I finally added filtration things improved a lot. Recently, however, algal populations started to climb again, and I had a small bloom of cyanobacteria. While I was gone over the weekend, I decided to switch off the light and just give the tank a little natural light that comes through the window. The effect was remarkable - after just 2.5 days of low light, the algal had thinned significantly. The plants look fine, the algae does not.

Pygmy corys

We took a trip to Houston this weekend, and I visited the most amazing fish store I have ever seen. Granted, that isn't all that difficult (given the selection where I am). The selection of fish and plants was amazing.

If I had that money (and tank space) I could have brought home dozens of cool fish. One of hte most remarkable fish I came across was Polypterus, a somewhat ugly, but truly fascinating-looking fish. But I really fell in love with the Pygmy corys. A little over a centrimetre long, they are very cory-like in their bahaviour, schooling around the tank, foraging along the bottom. The great thing about them is their size - I bought 10 of them, put them in my plant tank (which is only a 10-gallon tank) and I have a school of corys. I'd like to put them in the main tank eventually, but I am a little concerned that the angels might see them as food. The only problem with them is that they are similarly patterned to Otocinclus, and they don't seem to be good at telling the difference. The result in that they try to school with the Otocinclus. Since Otocinclus is a sucker-mouthed catfish, they prefer to hang onto the glass, not be harassed by smaller fish. (It's pretty remarkable to find yourself thinking of Otocinclus as "the bigger fish").