Had 16 ember tetras and 3 corys with a U4 filter in a Roma 125. I now have 4 claros on their own in the same tank (embers and corys in different tank) where there’s nitrite showing at 0.5 on API liquid test and 1/1.5 on Nt Labs. One claro is adult sized, the other 3 are juveniles.
Last time I had a nitrite spike after treatment in a different tank I didn’t interfere and it fixed itself.
How long would you leave it before doing a water change? Would it be an idea to use a turkey baster to remove excess waste between changes?
I could get 1 oz of Fritz zyme turbo 700 tomorrow but don’t like adding these things as never had any success with bacteria, and the fish are wild caught so nervous it could have a worse effect than nitrite. This brand is 15 x the strength. However if I did decide to do this would I need to do a water change before? And if the nitrite levels stayed roughly the same (under 2) what size change would you do? I was thinking 20% max to not disturb the cycle further but curious what you’d do. It does need some nitrite to cycle through.
Part of the problem here is probably that they don’t eat the food when I put it in so it’s sitting there a while. Feeding bug bite bottlm feeder and courgette, tried an algae wafer but it clouded the water so will stick to courgette. I have repashy soilent green which I could also try them on as it’s supposed to not mess the water up.
The filter was fishless cycled before the embers and corys. They were in there 2 weeks with one nitrite reading of fractionally above zero but apart from that was fine.
When nitrite is present a large water change is necessary - it won't disturb the cycle as the bacteria are adhered to the filter media and some extent to surfaces in the tank, not in the water column.Nitrite is highly toxic so you need to change enough to get it down to 0.25 or below. if you also double-dose Seachem Prime in the new water that will neutralise the nitrite for 24 hours, when another water change will be needed if it climbs again.
Everytime I’ve had nitrite and then done a water change it’s gone sky high straight after. I was told not to do a water change between fish but I did, and this is the outcome.
I’m already seriously worried that one fish is eating most of the food. They do not eat quickly when the food is put in so cannot remove excess food. I have cut the food back to every 2 days but I am now seriously worried I’m starving them as they are juvenile wild fish used to grazing.
In complete desperation here, they are such beautiful fish, and this was a one off opportunity to get them, not seem them for years. Very worried I’m killing them.
I think it would have risen just the same if you hadn't changed water - it was on it's way up so that continued . Honestly, your fish are at risk from the nitrite and water changes are the only way to get it down. The only other possibility is that you have nitrite in your supply - have you tested it? Definitely use a double dose of Prime as that will neutralise the nitrite and allow your fish to breathe properly. Nitrite affects the blood and prevents it from carrying oxygen efficiently, which is what kills fish.