I have had 3 corydoras Melini for a month in a 20g tall. I got 5, but 2 died in the first week (They are still all about 1-1.25in). Yes, the tank was cycled, but new.
This made me paranoid. I have waited a month to get more fish. The issue I was trying to address was very low kH
. I have added crushed coral, and things stabilized.
I got 6 young rasbora hets and a VERY small bristle nose pleco yesterday (1.25in). I was trying to be good and add the aquarium coop med trio to the tank since I never did it initially. (paraclense, maracyn, and ich x).
I measured the ammonia and nitrite twice today, and they were BOTH at 0.25. I added 2mL of Fritz complete at 5 hour intervals to address this. Nothing budged.
My corydoras started acting lethargic, and one developed a white spot by its mouth (he has always been the most active one). The new fish all look super active.
I panicked. Did a 40% water change and put the carbon back in my filter (Fluval aqua clear 30).
I donít have a quarantine tank. I am trying to cycle one, but if the meds kill bacteria anyway, is it worth it?
Should I try dosing the meds again? Maybe just maracyn? I have no experience, but from looking at descriptions, the spot may be colmnaris? How do I keep ammonia and nitrite in check after I add meds?
Thanks in advance for your help!