Big mistake

Two days ago, while fiddling with the filter in order to change the water flow, in an attempt to understand what better fits the archers, I forgot the filter off. It stayed like that the whole night, and I found out in the morning, yesterday. The risk is, of course, that the aerobic bacteria in there all died. A quick water test in the afternoon showed ammonia still lower than detectable (<0.01 mg/l), but nitrites between 0.1 and 0.2 mg/l. Bad. Quick water change, more than 50%. No food.

Water test today, NO2 at 0 mg/l both in the morning and in the afternoon. Tiny amount of food provided.