You really should have another heater, if just for backup (product failures, etc.) This treatment does take heat. (95's maybe enough, but you really have to hang with the duration, since that's the key, (IMO)..I've both fed, and not. It depends on the fish overall. They'll live without daily feeding. It happens all the time in the wild..to recap, slowly raise the temp, keep it high for many days, then take several days to return to normal (whatever that may be)...nothing quick, fast changes aren't good...Gary