Hi, I haven't time for trawling through the forum, and am praying that someone might be able to help quickly as my fish are suffering! My tank is planted, with bogwood and has been established since last Oct, I cycled it and tested for ammonia before I added any fish. We gradually added fish until january, when we had; 10 Neons 5 Peppered cory's (3 now deceased) 4 Bronze cory's (3 now deceased) 4 Otocinclus (3 now dead) 2 pairs of dwarf gourami's 5 lemon tetras 4 glass catfish (1 dead, one close, and one following the same pattern) Water perameters are ok, according to my test kits and also two local fish shops, PH 8.0, 0 ammonia 0ppm, nitrate <0.3ppm. We did not lose any fish for a good while, but recently we are really struggling, there are two patterns emerging, my cory's just turn over and die literally, as do the Otto's. My (wife's) beloved glass catfish will begin by swimming by the surface for a couple of days, then drop and lay on their sides on the bottom. They then will sporadically dive about before almost losing the will to live/suffocating, lasting 2 0r 3 horrible days. My remaining Oto does have red gills as well, and I have noticed a couple of lemon tetra's flashing against the bogwood and the whole lot seem to be a bit cranky, chasing each other and then hiding away. Obviously, it is awkward diagnosing in a forum, but I have even phoned the local vet and he couldn't help. It seems in the UK we have a "it's only a fish" situation,but that isn't for me,my fish are suffering, and I hate it. I do condition my water as I change it by the way,20% each week. Thanks for any help!!!!