offminded

Hey All,

How do you know what size water pump you need in order to pump water from the sump and back into the aquarium. My setup is a 55 gallon FOWLR with built in overflow...I am using a sump underneath my tank. Thanks for your help.

Dave

agsansoo

You want 3x-5x your display tank volume. So a 55 gal display x 3 = 165 gph, 55 x 5 = 275 gph. So anything from 165-275 gph of water movement through the sump. The reason for the slower water movement is to give the protein skimmer a better chance at skimming the DOC's (disolved organic compounds).

offminded

oh wow...i was way off. i purchased a water pump that pumps 700 + gph because the overflow in my tank can handle something like 600 or 700 gph for return water...i suppose i should take it back...do they make pumps that are adjustable so that i can raise and lower the flow rate?

Mike

Maybe I'm misunderstanding what you're asking, but you also need to take into account the plumbing. Pipe diameter, turns, valves, joints, all create friction along with the total length of the plumbing required to return water from the sump to the display tank. So, if your goal was 10x turnover in a 55 gallon tank, you'd want approx 550 gph going through the display. You'd then have to factor in the "head" which includes the length of the pipe and friction. So the pump required would have to be greater than 550 gph in order to account for head loss to get the water from the sump to the display.

Here's a good calculator you can use to calculate head loss: http://www.reefs.org/pumps/

agsansoo

700 gph at how many feet ? Every foot the water moves upwards, lessen the water pressure. My Rio 1700 is rated at 642 gph at 0 feet. But only 352 gph at 4 feet. That's the distance from the sump to the tank. Just tee it off back into the sump using a ball valve for water adjustment.

agsansoo

Nice pump calculate Mike !

Gozer_1

That's a fantastic calculator. Just the thing I needed. Well will need one of these days anyway lol. Here I was planning on a much larger pump than I needed. Thanks for the link Mike.

offminded

Holy toledo!!!! Just when i thought i was getting the hang of the whole aquarium thing...i am thrown another loop...ugh!!

Call me a total moron...but I just found the performance chart for my pump...and at 4 t0 6 feet the flow rate is approximately 400 down to 200 gph...looks like i'll be returning that one and getting a new one...what an idiot i am.

Now...can someone enlighten me on ball valves...it seems like they can help regulate the flow of the water? am i on the right track??

Just when i think i am somewhat smarter than a fish tank...i am proven wrong

offminded

is 10x turnover in my tank sufficient? should i shoot for more?

agsansoo

Ball valves are use to direct or redirect flow, not so mush to restrict flow. I try not to restrict flow from the pump. This should always be wide open (saves wear and tear on the pump, along with heat issues). Teeing the return line back into the sump will reduce flow back in to the display tank. Thus reducing the overall flow through the sump.

offminded

sorry for sounding like an idiot...but what do you mean by teeing the return line back?

agsansoo

OK .. In the picture you can see two ball valves. One right above the return pump, the other above the refugium. The one above the fuge is regulating (reducing) the flow of water back into the sump (return section). The tee is right against the back wall of the cabinet. I hope this helps a little.

agsansoo

This depends on what type of substrate you have. The finer the substrate, the lower the turnover. 10x - 20x for fine sand is about right. Newer opinions in reek keeping is to setting the flow as high as you can without causing a sand storm. My barebottom is around 40x - 60x !

offminded

thanks for the photo...it helps a lot.

i think i am shooting for 20 - 30 x tank volume...this would be inclusive of my skimmer, return pump, and power heads that i have...