Sometimes after a long time of no water changes in a large tank with big messy fish, they get used to it. The pH will decrease to the point where there wont be ammonia but ammonium. Ammonium is non toxic to the fish. So the beneficial bacteria dies, the pH keeps diving and the ammonium is not hurting the fish but building up. After you do a large water change to compensate for the negligence, the ammonium converts into ammonia, with no beneficial bacteria to break it down. So high ammonia levels will appear and no beneficial bacteria to break it down. This results in recycling the whole tank.
So keep doing large water changes every day for a while to get it back under control. I may be wrong but i read this in a magazine and i have seen it happen to a lot of other people. Check your water parameters. Also if there is chlorine in the water, it will kill the beneficial bacteria.
Good luck
So keep doing large water changes every day for a while to get it back under control. I may be wrong but i read this in a magazine and i have seen it happen to a lot of other people. Check your water parameters. Also if there is chlorine in the water, it will kill the beneficial bacteria.
Good luck
