I purchased a 75g tank used that came with 7 fish I slowing added fish and recently starting losing them. I tried treating the tank with copper. I was losing 1-2 fish a day until I had just one yellow goby left. A couple days ago I noticed the water shocked me and one of my fans was bad. I thought that I had a case of ick. I made the mistake of not using a quarantine tank. Could it have just been the electricity in the tank killing my fish? They were turning pale and very weak before dying. Regardless I will now be using a qt, ground plug, gfci. Thank you in advance