Return pump

[cristianD2000]

I have a 125g tank and was wondering if I can use a quiet one pro 758GPH pump I want to use for return sump. Attached are the pics of plumbing and pump. It's a 30g sump tank.

 

[WVNed]

You could but I am using a 700gph pump, Sicce 3.0 on a 75 gallon tank. It is not too much at all. With head and bends you are only getting 500gph. You will get answers all over the place here but I try to get 6x tank volume actual flow when I buy a pump.

 

[BZOFIQ]

Little under powered for 125 but yes it can be used.

 

[cristianD2000]

You could but I am using a 700gph pump, Sicce 3.0 on a 75 gallon tank. It is not too much at all. With head and bends you are only getting 500gph. You will get answers all over the place here but I try to get 6x tank volume actual flow when I buy a pump.

Thanks, with the 758 that averages out to 6

 

[cristianD2000]

Little under powered for 125 but yes it can be used.

I guess I can try it out and see how it goes and upgrade later.

 

[BZOFIQ]

I guess I can try it out and see how it goes and upgrade later.

Absolutely. Easy enough if you're using unions

 

[BZOFIQ]

Thanks, with the 758 that averages out to 6

Depending on number of "kinks" and head pressure that number is probably going to be around 400GPH, possibly less. Just try it.

 

[WVNed]

If it has to pump water 3 ft up to the tank plus the elbows you are looking at ~ 550gpph

I would go with the 4000 for $4 more.

 

[DFR]

If you already have the pump go for it, all the return pump really does is return water.
However just as an FWI, I typically shoot for 5-10x turnover between the tank and sump. Most sumps are located under the aquarium, and need return pump to push water 4-5feet vertically back to the aquarium. So normally the flow rate is about half (this is just the estimate I go with, not exact but close enough for me) of the rated flow by time it reaches back to the tank.
Now that 5-10x turnover is really just for efficiency purposes and really depends on filtration you have in the sump. For skimmers, reactors or anything with a lower flow rate pump, 5-10x is fine. For algae, mechanical filters, etc, you can go higher. Basically you don’t want the filtration in your sump to be reprocessing water it already filtered, as well as you don’t want all the water to bypass your filter before having a chance to be processed.
Generally, for a 125 gallon tank try to look at pumps rated around 1250g/h.