Three days ago I pulled 9 fish out of my tank; two days ago I added 3 fish, yesterday I added 19 fish, and today I added 7 fish. Sounds scary, right? Not so much when the 9 were 6″ adults and the 29 are all 1.5″ or smaller. Mass matters to the bioload.
Water parameters, several hours after adding the last 7 fish: ammonia, zero; nitrite, zero; nitrate, 5 ppm.
Last time I tested nitrates, they were somewhere between 10 and 20 ppm. I guess the two fairly large water changes I did after pulling out all the rockwork to catch the big guys dropped it down by ~10 ppm. Despite all the crud that’s no doubt filling up my filter sponges!
My one concession to the fragility of the biological filtration system is that I’m going to put off the regular filter cleaning for at least a week. I want the colonies that were on the rocks to have a chance to recover. They got dried out, and who knows whether the critters have a viable hibernation for that! It’s not likely to have had any effect on the brush algae, more’s the pity. But I’ll leave the filter untouched for now, so those colonies remain undisturbed. Especially since the nitrate’s so low! I’ll have to keep testing nitrate, see how fast it rises over this next week.
I have a horde of small fish in my tank. 🙂 The adult male saulosi doesn’t seem pleased – every time I added another batch he flipped out and started swimming against the glass. I can imagine him thinking “Get me out! Get me out!” but of course I’m not sure what’s going on in that tiny brain. He’s definitely stressed, but now that I’ve checked the nitrogen cycle elements, I’m thinking it’s a psychological problem and not due to anything in the water. None of the other fish are upset, either. Since he’s the largest fish left (barring the bristlenose pleco), maybe he thinks he’s next to be caught and vanished!