There's a difference between using a regular heater diy inline vs something like the hydro where water heats on contact. I much prefer the hydro where water gets heated immediately without delay. I think all heaters should be that way. I wish there was a way to set it up for a HOB filter.
I have a reef keeper elite that will be running in this tank. It has a heater control but I'd want a back up. Still trying to decide if I want to do inline or in the tank. Have people had leak issues with the rainbow unit?