Alright so I'll try to keep this short. I have a 210 gallon freshwater tank that I am completely redesigning. I am building a new stand and canopy and redoing everything. I really want to put a refugium on the tank using a 65 gallon measuring 48x18x17. The way my I'm building my stand the refugium is going to be visible as a secondary display tank that I plan on keeping plants in as well as possibly a few dwarf Indian puffers and some hillstream loaches. I like being different and thinking outside of the box when it comes to stuff like this so that's why I'm doing it. My questions are in regards to my refugium. I am new to this. When I place a heater in the refugium is it supposed to be large enough to heat the primary tank or just the refugium? Also I've heard that when you lose power you risk the main tank overflowing the refugium. Is this corrected by putting a check valve in and if so does it need to be in both the intake and return or just one or the other. Lastly i plan on having a CO2 system so should i have diffusers in both main and refugium or just one or the other? Sorry this is so long just really eager to get this project off the ground.