How Much GFO for a 75 Gallon?


New member
I just ordered a GFO reactor and pump from BRS along with some GFO, but Ive never used any of this stuff before. How much GFO should I use for a 75 gallon mixed reef with a 30 gallon sump?


New member
I use about 1/3 of a cup. I'd start with about 1/4 cup and see how that works. It's easy to use too much and strip too much too fast.


Active member
Use the GFO calculator on the BRS site. The amount varies by type of GFO. I started with half the recommended amount, then slowly worked up to the recommeded amount.


New member
I would start with 1/2 of what BRS recommend, test your effluent weekly to make sure is not exhausted and start leaching phosphate back into your system.