Switching tanks.. need some advice

[NickB]

so i had a problem about a month and half ago where my fish got sick and three of them died. the one that lived i moved into a 20 gal tank along with my canister filter from my 60 gal.. i broke the 60 gal down completly and cleaned everything. Its been about a month and a half now and i decided to get 2 more fish. After i brought them home i transferred all the water and filter back to my 55 gal and acclimated the fish into the tank. ive been adding five gallons a day for the last 5 days and the tanks almost full..ive been testing the water everyday and all my levels are the same as they been for 3 months. Today i noticed there was a faint smell coming from the water. Im just curious on what problems i might run into? and what the smell is from?

thanks nick

[DerekFF]

uhm....did you clean the filter and media? Whatever was in the tank before has a high probability of being in your filter too.

[NickB]

the discus got sick from tetras that were in the tank.. i treated the tank and filter. then switched to a smaller tank. and ive rinsed the filter and media in tank water before i put it back on the 60 gal