What size recirc pump for my 30 (somthing) " taLL 6" recirc. skimmer?

[The Propagator]

What size recirculating pump should I use on my 6" O.D x 5.875 I.D.  (17 7/8" tall reaction chamber).

650, 750, or 950 ?
The only holding my project back is determining pump size.
Help a brother out guys ! 
( pics on the way. probably tonight)
D

[verper]

What brand pumps are 650, 750, and 950?

A lot of people are using the genx 4100 with mesh wheel mod.  There is a thread in the DIY forum on RC about it.

I use a Sedra 9000 on my 8" wide, 30" tall ASM G4x.  Small maxijet for a feed  pump.

[Viggen]

1st, you take the size of your aquarium in gallons

2nd you multiply that number by either 1 or 1.5

3rd you find a pump that puts a GPH rating in that area

For me & my 260gallon tank, I use a eheim 1250 which if I recall does about 300 gph.  My skimmer is a ER RC500 which is 12x30 in

[The Propagator]

Those were rough numbers.
Gen-x makes a 636 gph pump
octopus makes a 750 gph pump
sedra makes a 900 gph pump
Mag makes a 950 gph pump ect ect....

Thanks Gary,
I want to make this monster capable of skimming up to 350 or so gallons when I get my tub systems set up and running. I want this to be able to handle it.
I can always just use this one for now and make another taller reaction chamber but it's REALY hard to find acrylic tube under 6 foot lengths at a decent price.
the 6" 17 7/8" section I purchased came from Ebay and was $28.83 shipped.
That same pipe is only sold in 6 foot and 10 foot sections eslwhere and for around $30.00 per foot shipped.
That would blow my cost effective advantaged out of the water.
For 8" pipe its around $40.00 per foot shipped.