It all started about a week ago. I noticed a white coating ( like velvet) on my angelfish and they where breating heavy and then they started dying off one by one. About 2 weeks ago, I bought 2 new Koi Angelfish, some plants, 1 Neon Blue Dwarf Gourami and a sailfin molly. Them four fish died first and then my other angelfish stared to die. About one every two days. I have tried raising the temp., adding salt, using copper safe, two treatments of Furan-2(anti-parasitic med.) and tonight I'm trying clout. I also did 25% water change with each treatment. Does anybody have any suggestions?
Ammonia 0.25 ppm after first treatment of med.
Nitrate 160 ppm
Nitrite always 0
PH always around 7.2
GH 300ppm very hard
55 Gal. Freshwater Under Ground Filter(power heads), Old Hang-On Filter with Floss (Have XP2 FilStar Canister Filter on order, but afraid to put on this tank until I get it cleared up!)
2 Koi Angels (Bought 2 weeks ago and died first)
3 Sailfin Molly (Bought one 2 weeks ago and died first) 2 still alive
2 Silver angelfish (died)
2 Black Angel fish still alive
2 marble angelfish one died
3 cory catfish all alive
2 Neon Blue Dwarf Gourami the one I bought 2 weeks ago died