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.

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). 

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.

The plant tank

About a week ago I moved the breeding pair of Macropodus out of the plant tank into the main tank. Above all else, I wanted them to just stop breeding, but I also was afraid that they were harassing the Otocinclus too much. But then, last weekend, on a whim we bought a couple of fighters. The male was the kind of colourless/golden fish you see from time to time these days, while the female was either the same of what we used to call "pearl". I figured the plant tank would make a good quarantine tank for them, although I was rather unhappy with the fact that this would mean that the Macropodus fry would become fish food. (Remarkably, several of them survived a week with the fighters).

Once I got them home I realised how small the female was. Still, given the size of the Macropodus female which had just bred in that tank, I wasn't going to rule out the possibility that she was ready to breed. Since the male built such an extensive nest, I let her out, but she was obviously uninterested. After a few hours I separated them again. Although I tried several times, I was unsuccessful. After a week of isolation I put them into the main tank. Maybe once she gets bigger I will give it another shot.

One big problem in the plant tank has been algal growth - a brownish, filamentous alga has gradually overgrown everything. Although I have removed a lot of it, the tank is still overrun with it. The two Otocinclus are either uninterested in this type of algae, or are simply overwhelmed, so I decided to buy a few more (I had wanted more than two when I bought these, but they only had two). And, since I've always wanted more corys, I bought a few of them as well - a new species, bringing my cory diversity to 4 species. I figured that since they root around on the bottom a lot more, they are likely to increase habitat heterogeneity. I'm hoping that this will have some effect on the algal overgrowth.

Macropodus fry

The Macropodus nest was in a difficult place to see easily, so it was hard to see if there were eggs, but after a few days I started seeing the fry. Today there are 30-40 fry (maybe more) on the glass below the nest. Now I have the great challenge - do I feed them? I don't want to - I have more Macropodus than I know what to do with. On the other hand, I don't feel comfortable with the idea of just letting them starve to death (letting them get eaten doesn't upset me, but letting them starve does, for whatever reason.

The other issue is algal growth. An awful lot of algae has grown along the glass in the tank - mostly along the right side (where the light is) especially along the back (which is against the window). I'm also getting algal growth (maybe cyanobacteria) along some of the gravel. On one hand, since my main interest is plant growth, this should not be a bad thing. On the other hand, the algae can overgrow the plants. One solution might be more plants, another is to get some more Otocinclus (since I only have one in the main tank, they could move over once they have acclimated and knocked the algae back a bit).