flow rates

[umphlettm]

hello everyone.
im not sure if this goes here so forgive me if it doesnt. im wondering about flow rates when setting up a salt water tank (55 gallon). what pump size (gph) would i need. is there any forums that go into detail about setting up a tank from starting up to actual running (im far from being a genius ha ha). so far im thinking of a 55 gallon with a 20 gallon sump and a protein skimmer. its gonna be a while before i start but i want to have a good understanding of how to set everything up.

thanks,
umphlettm

[Bifferwine]

For a return pump from the sump to the main tank, you want something rated at least 10 times your tank size. And you have to take into account the distance that the water has to travel through plumbing. So for a 55 gallon tank, I'd shoot for a return pump rated at around 600 gph.

[McCrary]

The size of your return pump shouldn't be based on the size of the tank, but rather the size of the sump. The water that is returned to the tank must flow through the sump, if too much water goes through the sump you will have a problem with microbubbles. The biggest determinant for the amount of water the return pump should provide is based on the width of the sump. A sump, like a 20 gallon, that is 12" wide will not handle 600gph through it well. My sump is 12" wide and 36" long, it only gets about 400gph through it at the most. The Eheim 1262 I use is rated for 900gph, but is split between returning water to the tank and to the fuge.

People often try to provide flow through their return pump, this usually creates problems as the return pump is simply used to return water to the tank after it has been filtered. A return pump rated for 250gph would be a good choice in my experience.

[Bifferwine]

You won't have problems with microbubbles if you have a bubble trap in your sump.

[reeffreak]

A 250gph pump?Heck might as well use a maxijet for a return.I agree 500-600gph would be good.A mag 7 would be about perfect,its rated at 700gph at zero head height/500gph at 4ft. head height.

[Bifferwine]

I ran a 20 gallon sump on my old 55 gallon tank with an Eheim 1262 as the return pump for almost two years and had no microbubble problems. It worked well for my tank, it wasn't too much flow, as I still needed a few powerheads in the tank.

[McCrary]

Originally Posted by reeffreak

A 250gph pump?Heck might as well use a maxijet for a return.I agree 500-600gph would be good.A mag 7 would be about perfect,its rated at 700gph at zero head height/500gph at 4ft. head height.

Lol, yea when I setup my 110 I was going to put about 1000gph through the sump and people freaked. I thing is that you have to differentiate between the needs of the sump and the circulation within the tank. The sump and return pump shouldn't be used for anything but filtering the water. A pump that returns 250gph will still be cycling the water in the tank through the sump about 5 times an hour. Use powerheads or a closed loop for circulation within the tank. I think that a lot of people want to put a lot of water through the sump, but it just isn't necessary. This isn't to say that it can't and isn't done, but the filtration seems to work better when the water through the sump is nice and slow. I am not trying to go against the grain or undermine the advice that you and Sarah are giving, this is just the way that I have always been told to do things.