Confused about GPH


New member
I have a 120g Mega-Flow tank drilled for 2 overflows and rated at 1200gph. I plan on using a sump/refugium as well. I have read that your return pump should only push 5X +/- your tank volume. Am I supposed to get a return pump based on 5X tank volume and add other devices for additional flow or get a return pump that will get me closer to the 1200gph rating? I would like to keep the tank as free from additional hardware as possible.
yep you will want a return pump rated around 3-5x the tank so 360gph - 600gph. or mainly what ever your skimmer can handle might be slower, might be faster. then the rest of your flow from either powerheads or a closed loop. a closed loop will look much cleaner if thats what your after.
I have the same tank and run a mag 12. I also have several powerheads that add to the flow. Altogether I have 4,100 gph in the tank. I do think it may be a tad much. To cut it back I may add a wave maker to lower the amount of movement from the powerheads so that only half are on at one time. Honestly the fish, coral, and anemone all seem to enjoy the extra water movement.