Strange tank crash - tests well but fish gasping?
Hey guys, a bit of a complex disaster so any help would be appreciated:
I have a 55 gal that I had been growing using the dry start method. Some of the substrate was used in a previous tank. Also had my filter from my previous tank so I run that with an Eheim. I had about 15-20 platys, tetra, dwarf gourami etc. in there with loads of plants and floaters. All the fish seemed very happy.
A few days ago I added a big bag of cherry shrimp to clean the tank up. They seemed to be fine and they were eating, but when I woke up in the morning and for an unknown reason they were ALL dead and all the tetras were dead or dying, presumably as a result of the ammonia the dead shrimp released. I have a nano tank and moved the platys to the nano, I fished out as much dead stuff as possible and I have been doing water changes. I noticed that the gouramis (and a pleco) seemed to be fine and would go to the surface for air every now and again, presumably because the gouramis are labyrinth fish and can breathe from the surface and the pleco is hardy, but the one platy I left in the tank to test it is still gasping for air at the surface. A medium amount of green thread algae has formed but unfortunately, obviously, I do not want to push shrimp in to clear it out right now.
There is loads of aeration from the two filters and plants, my pH is 7 and my nitrites test reads absolute 0 (it's the only one I have right now, I guess I need to get an ammonia one - but I can't imagine ammonia being sky high if nitrites is 0?). The temperature is slightly high but the platys in my nano tank are very happy and so I presume that's not an issue.
Could the sky-rocketing ammonia have killed off all the bacteria and re-cycled the tank? Or could another issue be causing the platy to stay at the surface of the water seeing as my nitrites are at zero?
In addition, the fish, the platy in particular, have long white poop - perhaps there is some kind of parasite infection (I live in China and the fish are generally kept by the shops in rather poor standards so I would not be surprised). I presume this can't be the main problem as the other fish in the other tank that have had the same exposure seem to be fine, but just wanted to mention.
Last edited by Hexagonalbolts; 06-17-2018 at 05:40 PM.