Single pump or double pumps better?

[Dresden]

Would it be better to go with two mag 9 pumps? or one 18 mag. Or another brand? CPR150 overflow, 5ft piping up? Cement floor also.

[TANGOMAN]

Do you have spec's. on flow in comparison to height(head) ?
I'd be curious if the mag 9 head is equal to 1/2 of the head spec. of a mag 18. If not, I'd be inclined to go with a single pump. A benefit to two pumps is, if one fails, there's still one running. Dual pumps should be plumbed with individual returns.
Is this a basement sump arrangement ? Are the Mag 18 flow rates going to give ya' a good "turnover rate"? I like my mag 12. It is noisier than the "Quiet One" I have running on a different tank but the flow rates are obviously less than the mag 18 and probably insufficient for your needs.
It may be more "economical" to go with a single, "beefier" pump...

[Dresden]

lets seee, the CPR overflow provides 1600gph of flow outta the tank. the refugium and sump are under the tank in the same cabinet
18g sump 18gal refugium. I have heard u want a little less flow return than your overflow.

[Jack]

Mag 18 will give you about 1200gph @ 5' head. I have a Mag 18 but haven't used it on my new tank yet so I can't comment on it's preformance. I can maybe update you awhile down the road.

[canadawest]

My brother has just gotten into the hobby with a new 55gal tank with 20gal sump. We orginally decided he would only need a MAG 12, but J&L didn't have any so he ended up buying a MAG 18. He also purchased a CPR CS102 (dual 1" overflow rated at 1400GPH). He's just finally gotten it filled with water and is running the system. The MAG 18 is a perfect match, albeit throttled back a tiny bit with a ball valve inline on the return side. Plumbing is 1" PVC with a total length of 4' up & 5 - 90degree elbows. I'd say with a CS150, you'd have no problems whatsoever, especially after you factor in head pressure.

It's recommended that you have 200GPH less than your overflow is rated for coming back into your tank. A MAG 18 is rated at 1200GPH @ 5' head, so you'll have more than enough overflow ability with your CS150 capable of up to 1600GPH.

I always say, buy a little more pump than you think you'll need! In this case a MAG 18 would be a good match for you I think.

As for using 1 or 2 pumps? The only reason to run two pumps is redundancy. A larger single pump will be cheaper than two smaller ones, both in initial cost and in cost to operate. Also, I'm not sure that just by combining two smaller pumps on one return that you actually get the benefit of doubling the head pressure ability (but don't quote me on that).

[reefburnaby]

Hi,

I would go for a Mak4. A bit more expensive, but they will last a very long time, they are more power efficient.

- Victor.

[Dresden]

thankyou for the detailed info very helpful and i'll ponder my choices tonight and make a decision. Either Mak-4 or a mag 18-24

[BC_Grl]

We are using the Mag 18 and it is NOISY!! :shock: You don't realize how noisy it is until you try turning on the TV. I am sure there is a quieter pump...

[Dresden]

i read somewhere you can use jacuzzi pumps for you tank, wonder if they have quieter ones.