it has died so i went over today and got some new fish i got and alge eater and an upside down catfish and a femal guppy. They gave me some stress coat to help introduce the new fish into the tank. Well now i did a water test and my results are the same till the nitrite which has went up to 4 and my nitrate is up to 20 so i shold do another 50% water change but should i leave the fish in and the water is village water and i dont know how to heat the water up to 76 to put it back in the tank with out puting it in and letting it heat up with the fish in it or using warm water???