Return Pump sizing

[srizzutto]

Hi all

I am in the process of setting up a 75 gallon Tank
If i remember correctly I should shoot for 10x the gallons for water flow
I believe years ago when I tried to achieve this flow with just the return pump, my sump was like a raging river and i had to downsize the return pump
I have a Mag 9.5 but i think this will be way too much
I also have an eheim 1250 but at 350gph flat, I think this may not be enough
My head height is about 3'

Thoughts?

 

[mariobrothersleeve]

It all depends.

If you run more flow thru the sump, on the return you could install an oscillator and run smaller powerheads.
It is a preference and what corals you have.

 

[salt_for_brains]

Like Mario said it depends a lot on what you are planning on keeping in the tank. I don't like rapids in the sump so I try to keep it around 3-5x in the sump and use powerheads in the display tank to achieve the higher turnover rates.

 

[srizzutto]

ok
then maybe i can make the Ehiem work
I would prefer a slower flow in the sump for skimming purposes

The tank will be 3 or 4 fish, softies and hopefully a bubble nem

thanks for the thoughts

 

[DVH]

This will depend on if you have a built in overflow or your using a hang on u-tube overflow. most hang on overflows depending on size, have a limit that they can handle. Same goes for a built in version. If its a hang on version, what I do with all my tanks that have this type of overflow, is use a larger pump, but put a control valve in line on its way back to the tank. If using a hang on, get things fired up and pay attention to the u-tube. Set your inline control valve so that your flow doesn't allow any bubbles to form at the top of your u-tube. You will than be at your max flow rate. If you want slower flow in the sump, consider getting a filter sock and zip tie it to your drain line. Hope this helps.

 

[DVH]

Oh, BTW, I'm using a mag 9.5 on my 75 Gallon right now. With about 3' of head. It works perfect. My overflow is a hang on style, rated for 350 GPH.

 

[srizzutto]

Thanks DVH
I'm surprised that the 9.5 isn't just sending a raging current through your sump
Anyway, I think im going for the mag 7, The mag 5 im using isn't enough. I do have a built in overflow. I will put a ball valve on the return but I doubt i will need it.