what size?

[The Reefer91]

which size of pump do i need? i'm definately getting this brand, just not sure what size. i will have several powerheads equaling over 1000gph, so consider that. i need to be able to buy one cheap. i was considering going with the 24mag drive

http://bigalsonline.com/catalog/product.xml?product_id=27415&category_id=3855&pcid1=2181

http://bigalsonline.com/catalog/product.xml?product_id=27405&category_id=3855&pcid1=2181

http://bigalsonline.com/catalog/product.xml?product_id=27401&category_id=3855&pcid1=2181

[SeanT]

Ummm...what is this pump going to be doing?

[The Reefer91]

returning the water from the sump. it will have 2 exits(2 different overflow boxes)

[SeanT]

You have got to learn to give us more meat on the bone. :)
What size tank, sump etc.

[reefD]

if your over head from pump to display is normal(3-6 feet) then those pumps is plenty and then some. try something lower. those pumps are good for long distance plumbing like 20 feet.

[reefD]

that will work ...your flow will be impressive! maybe too much .add a valve for control if too high.

[The Reefer91]

ok, here's the facts. 55g sump. 125g tank. like, 3-4 ft of PVC piping. i will have a ball valve to slow it down. could i get by with the 18?

[moumda]

What are you planning to have for livestock in your tank? If you're going to go fish only the 18 would be plenty, if you're going to go sps you'll need more flow. IMO, I would go with a return pump in the 10-15 times total volume (in your case about 165 since your sump won't be full). Then if you want more flow you can go closed loop or tunze streams or the like.