I am planning on using heating elements in my sump plugged into a controller plugged into my apex. I originally bought x3 600w BRS heaters. I was going to return them for x3 300w Eheims. This will give me an added layer of protection and less wattage. Eheim rates the 300w up to 264g. But, everywhere I see it’s almost 5w per gallon. In total when my system is fully operational, I’ll have about 550g in my system. What are you using and what do you recommend?