After my tank was about 4 months old I had 18 fish die in the span of two days. Fish had a bit of ick but white round colonies in gills. LFS gave me meds for gill flukes and 7 fish made it. It has been 8 months and it seems to be repeating itself. I have a 70 gallon tank, crushed coral substrate, ehiem 2026 prof 11, powerhead (600 g/h). I have 6 electric yellows, 3 ob peacocks, 3 ruby red peacocks, 2 black calvus, 2 red fin borleyi, 2 catfish, 3 monos, 3 strawberry peacocks, and 3 clown loaches. I have raised temp to 83, added salt and used nox - ick half dose for three days. Fish still have ick and I believe I will wake up to more dead fish tomorrow. I may have been a bit slow to act on the ick as I was away and when I returned my wife said the fish didn't look right. Gone for three days. I do not have a water test kit but am getting the water tested tomorrow. I clean fish tank each week and replace 25 % of water and use a declorinator always as well as 2 tbs of aquarium salt. Temp is 81 degrees. If ick is left too long does it go into the gills? Any help would be appreciated.