What are the best heaters for small tanks? I'm thinking 2.5 gallon up to 5 gallon. I use these tanks for fry grow out tanks and sick tanks and the heaters they make for small tanks like this are mostly crap. I can't tell a lot from Amazon reviews either because no offense but most reviews are from desktop aquarium kits for goldfish and other inappropriate and ignorant (lack of knowledge, I'm NOT calling anyone stupid) use so I can't trust them.