I admittedly spend less focus on our lab's quarantine tanks than I should. I focus more of my water quality attention on my main holding systems, and they are running great. However the problem I run into is that when I get a sudden influx of new fish in our collection our quarantine system are in poor balance, and I have to spend a lot of time doing water changes to keep the fish healthy and infections down. To be perfectly honest that lack of attention has often made my life and the life of the fish harder.
In an effort to amend that, I have been trying to cycle my quarantine tanks with a few small bullheads. My plan is to keep them or other small fish in the tanks at all times so that I can already have nice cycled tanks ready to receive any new quarantine fish or sick fish from my main systems. Currently most of the tanks are doing well in the cycling process. All but one of the tanks actually has fish that need to be quarantined in them. The one that doesn't is holding a few bullhead. The issue I'm having with that particular tank keeps getting crazy pH drops overnight...like from 7.2 to 4.2. Is this simply a cycle crash? Is there any suggestions going forward?
The quarantien systems consist of the following...
(3) 20 gallon tanks, no substrate, each with a submersible UV, each with an Aquaclear 50 hanging filter
(2) 100 gallon tank, no substrate, each with two submersible UVs, each with two Aquaclear 70 hanging filters
One of the things I was gonna try was some crushed oyster shell in a filter bag to help buffer the pH. I've been adding baking soda to the tanks to keep them stable, but it's just not working for this particular tank. Any thoughts from my fellow NANFAns