What mag-drive for a 100g 4'x3'x18" Tank?

[Dlckwood]

I was thinking either the 18 or the 24. Will this be too much flow? I also has 2 seio 1100's in the tank.
Thanks
David

[bornfree]

How is the mag to be used. For a sump pump, closed loop, then we'll know how to answer you.

[Dlckwood]

Its going to be used as a sump return.
David

[bornfree]

What size overflow and what's your head height? Depending what these are you could use a mag 18 or 24 but get a ball valve in the plumbing to regulate your return flow.

[Dlckwood]

The head is about 5 feet and my overflow is 2 "1 1/2" inch portholes. The sump is riged up now so if there is a power failure it wont overflow.
David

[sjm817]

I'd go Mag7 - 9.5 and that is overkill for a return pump.

[Dlckwood]

I have a Gen-x gx-4100 right now and its just not enough flow. I have my return in the tank as 4, 1/2 inch pipes and the water just tricles out.
David

[bornfree]

The mag 18 is 1125 gal at 6 feet, mag 24 is 1355 at 6 feet. Get the mag 24 with a ball valve if it is a bit to much flow you can adjust with the ball valve. A mag7 is 400 gal at 6 feet, a mag 9.5 is 760 at 6 feet, barely enough for half of your output.

[sjm817]

And what is wrong with 400 or 760 GPH for a return? That is more than enough for display -> sump flow. You dont want 1000+ GPH screaming through your sump.

[bornfree]

If your overflow is only 400 - 760 then fine, but he has two 1 1/2 pipes more like about 1400 gph. If you want to take full advantage of this match the return pump to the overflow volume.

[bornfree]

I know quite a few people using mag 18's as a return pump for a 1000 gal overflow. Works just fine and you don't need a lot of powerheads in the main tank to boost up waterflow.

[onehundred20]

id say use a mag 7 at most 9.5, use powerheads or closed loop for your flow.

[sjm817]

Originally posted by bornfree
If your overflow is only 400 - 760 then fine, but he has two 1 1/2 pipes more like about 1400 gph. If you want to take full advantage of this match the return pump to the overflow volume.

There is no reason to use excessive return flow just because the overflows have the capacity unless you like noise, microbubbles, heat, high electricity use, and best of all, reduced skimmer performance.

[DaddyJax]

I use an mag 18 on my 90g and it does great. I also keep sps and the flow is crucial. A question might be better to ask what kind of tank is it going to be? Mag 18 might not be needed for some livestock and perfect for others.

[sjm817]

Daddyjax, how big is your sump? What is the head height? What diameter plumbing and outlets are you using on the Mag18?

[DaddyJax]

Dual 1 1/2" drains and 2 1/2" return. 5' head. 50g sump and two turboflotor skimmers. I have the ruturn split into four outlets.