My neighbors fan is off balance and there is an audible humm in my apartment. The fan is in the room below my 50 gal. I would imagine this is very bad for the fish but can't do much about it. Mentioned it to neighbor already. Fish in that tank are dying and colors are faded. Added some stress coat and will check parameters tonight. Tank has been set up for about a year and healthy. Minor change in fish stock - took out 5" common pl*co and added a small dwarf pl*co but no other changes. SOME of the fish had nip marks and I am wondering if it leporinus fasciatus for some of the deaths. But some had no marks and colors are faded on most. Ideas ????