Well, we created
something.
I should have posted more about the chemistry. It's been quite an eye-opener for us. The water here in Glasgow is so soft, and so lacking in minerals, that the "nitrogen cycle" crashed and we are back at the stage of trying to get it restarted. Basically it goes - the fish put off nitrite and ammonia. Some of which gets absorbed by the plants, who are happy to have it, but the rest sort of floats around in the water. Both are bad for the fish. The higher the concentrations, the worse - nitrite can interfere with the fish's ability to use oxygen. So the solution to that is to get the nitrogen cycle established. There are bacteria that eat ammonia and convert it to nitrite, and other bacteria that eat nitrite and produce nitrate. Nitrate, in low quantities, is harmless to the fish. The plants will eat it, and it'll get flushed whenever I do a periodic water change. Having a stable cycle going in the tank also stabilizes the pH.
Unfortunately, although our tank was going great guns for a while there (ammonia dropping, nitrite dropping, nitrate stable) over a period of a couple of days that all just stopped cold. After much research and fiddling with the chemistry test tubes, it turns out that the pH of the water is too low to allow the bacteria to thrive. These particular fish are ok with it, but not the bacteria. The bogwood in the tank is just making it more acidic, too. Some of the plants are not doing well and had to come out - the mossballs went first. The grassy stuff - well BB and the boys root so much that they keep de-planting it, so it's being replaced with something they can't do that to. I had hoped that the grass would have been more established, as it was in there weeks before the fish just so it could have time to root properly, but alas, it's not working against the collective bulldozing power of BB&B.
I've had to find some dolomite (an alkaline mineral) and some crushed coral to add in to it. That has raised the pH slightly, but it's barely on the bottom of my measuring chart and tends to fall back below it if I don't keep a daily eye on it. I have to be extremely careful to make sure that the pH doesn't rise too quickly, too, so it's kind of a trial and error as to knowing how much to add. In the meantime I have a big bucket in the kitchen with dolomite and water in it, and the pH on that is much higher as it minerals disperse out into the bucket, so I can use it to mix with the replacement water I add to the tank every few days to try to bring the pH up slowly. (Too fast and Big Bertha and the Boys would suffer.) Over time the log will stop causing so much of a problem, but for now I have to test the water very few days and try to bring it up to a minimum standard.
The neons in the little tank that was Bertha's former home are doing much better. The water is sparkly clear, has had a few lumps of coral mixed in with the sand, and has a measurable pH. They are displaying and acting just as neons should do.
This is all very weird to me, because I've lived almost all my life in places that had extremely hard, mineral-laden water and I've never had to deal with water so much the opposite. I've actually sent off to Tesco for a few litres of still mineral water to add to the small tank, to see how that works out. (The pH on the Tesco water is 6.2 on one brand and 7.something on the other. It's the minerals I'm looking for.... at least it's cheap!)
Everybody does that to their first goldfish, don't they?
