I have a 75litre fresh water tank, I lost most of my fish to itch I have only got 3 tetras and 2 female fighting fish left. I have left my tank for 2 weeks and not added any new fish, done a water change and cleaned etc. The remaining fish seemed fine. Last week I brought 2 blue tetras and 2 gervace? tetras, I put them in the quarantine tank that I had set up, I didn't put a lid on the quarantine tank and the 2 little blue tetras jumped out, we found them on the floor in the morning,:duh:. Today the other 2 tetras seemed fine so I put them in the main tank, a few hours later one of them is not well, he is swimming straightup and down or just floating, very lethagic, I have transferred him back to the quarantine tank and medicated both tanks with melafix just to be safe, I have had a trouble free tank for 10 months and now feel as if it is all going wrong, how long should I have waited before adding new fish to my main tank, did I add them too soon after having problems with itch?