Subject: Re: Complicated?
by fcmf on 22/5/2020 13:24:00
Sorry to read about this horrible situation.
I think, for the foreseeable future, ensuring that water quality is kept good (ammonia and nitrite at 0, nitrates at no more than 20 above tap water level) is key. I wouldn't treat with further medication but instead focus on consistent water quality alone. The addition of the air stone was a good plan too. Best of luck that this helps the tank to settle down.
I notice you have a mix of hard water (guppies) and soft water (neon tetras) fish - one or the other may not fare as well generally (unless you've somehow customised the RO to be appropriate for the requirements of all fish*) and it might be that the medication sent them over the edge.
* https://www.seriouslyfish.com/knowledge-base/ will tell you the hardness/softness requirements for each species.