What pump should I use (What gph)??

I am setting up a 20 gallon long with a 20 gallon tall underneath it as a refugium. The 20 long will have 2 holes drilled in the back top corners with 3/4 pvc pipe leading down to the sump (gravity fed). I was wondering what pump should I use to return the water to the aquarium (about 2 feet back up) I was thinking a mag 3-350gph or 5-500gph (which would be better?). Also what size pvc pipe should I use for the return line? Any thoughts would be great, thanks.

 

Head Loss
^ head loss calculator (didn't find one on 3reef)

Measured my return rate using Mag 5 with under 3 feet vertical return and with was right at 240gph.... lost half capacity.

Good luck...

 

Well, when I bought this 90g display, it came with a Mag7 pump which was OK but way to small for good flow although the tank also came with 2 tunze powerheads. ;D

I'm rather impressed with Mag pumps. They're just standard issue workhorses...pointblank! Great price to. Anyway, very absolute minimal is something like 10x water volume.....20 & 20 are 40g's X 10 = 400gph. Don't forget you'll have sand & rock in there right? Also, this flow (10X) is probably best suited for softies but you can always augment with powerheads.

Now, some of the purests on here go with 20x or 40x volume for their SPS tanks plus they have powerheads inside as well. So, flow (gph) does depend on type of corals you plan to keep.

I've always stuck to gph 'rule-of-thumb' and always a bit above. As long as I was well above minimum, then I knew I'd be OK. Lastly, for an additional 15 0r 20 bucks, why don't you buy a Mag7 or 9? You can always plumb to run media reactors, turf scrubber, refugium, etc. from the return.

OK, hope this is help to you.

Good Luck.

p.s. never dealt with 20g before but I've always plumbed 1" out of the return and reduced to 3/4" up at the tank. You should be OK with 3/4" depending on which pump you buy.

 

Hey that helps a ton, I will be having live rock and sand along with at least one power head. I just want to get a feel for a sump/refugium on a small scale because in the future I want to do something similar with my 75 gallon. And on the plus side it adds a bigger water volume to the tank. Once again thanks