Another return pump sizing question


New member
I have a 120 gallon aqueon tank with the dual overflows (or as they call it, megaflow or something). Right now I am running a mag drive 9.5 but am thinking of changing to a sicce syncra. My skimmer has an input of 300 gph. I also have a brs dual reactor that has a maxijet 1200 (300 gph) pump but is restricted by, i'd say, 1/3. So, skimmer takes up 300 gph and reactors take up 300 (lets assume i have to run the reactors at full power for some reason, unlikely but i want the ability to do so). Thats 600 gph for those two. So my thoughts are:

1. If i want to plump my skimmer and reactors into the return pump, how much additional flow should I have? If I go with a syncra 4.0 (951 gph). At 5' head pressure that comes out to 700 gph. This, in theory, only leaves 100 gph excess through the sump.

2. Same scenario with a syncra 5.0, at 5' head pressure it comes out to 1,000 gph. So about 400 gph through the sump.

2. Run the skimmer and reactors on their own pumps like they are right now. What flow do you think I should go with. I was thinking a syncra 3.0 (714 gph, 550 gph at 5') as the wattage is almost half of my current mag drive.

Cobalt maxijet 1200: 20 watts each (one for skimmer, one for dual reactor)
Current mag drive 9.5: 93w
Syncra 3.0: 48w
4.0: 80w
5.0: 105w

so in terms of wattage
1. currently, mag drive 9.5 and two mj1200s: 133w
2. everything on the 4.0: 80w
3. everything on the 5.0: 105w
4. syncra 3.0 and two mj1200: 88w

What would you do? Are there any downsides to having everything run off of one pump except for having a few more valves, and the possibility of everything going out at once instead of one at a time? I like the idea of having everything on one pump but that may be asking for more issues than its worth. Also looks like it would take the most wattage. although less than my current setup.


New member
leave the mj's on the bra reactor ( the gph here is a factor as its gonna be different depending what media and how much you use, changes as sponges plug up etc. etc) and get whatever flavor of return pump you want with the correct gph for your height and plumbing. I like ocean runner pumps for internal return pumps myself would suggest a or3500 as perfect for your tank size, they last forever, impellers are cheap, and fairly quiet. have not played with the sicce return pumps, had a sicce on a mesh wheel once it was a very good pump.