Closed Loop (with a twist)

[Pez Vela]

Anthony (Mr. Calfo),

After reading most of the threads regarding closed loop mainfolds, I have come to realize that I need to pose my question to you, and others straight out.

First, here are my aquarium specifics..... My display is 54"L x 30"W x 24"H. It has an external overflow box (32"L x 6"W x 16"H) w/30 linear inches of overflow "teeth" and (2) 1.5" diameter "Durso" drain pipes. The overflow box/drains gravity feed my sump/fuge combo with returns to the display via a MAG18 pump. The sump return is comprised of a bottom mounted 3/4" diameter pvc pipe loop (under my live rock) with many holes drilled in it in an attempt to keep as much of the detritus as posssible suspended in the water column for collection by the overflow.

What I am upgrading is my closed loop. I just bought a Sequence Reeflo Dart (±3000GPH). My planned returns from the Dart are 1" diameter. They will all be drilled through the back & side walls of my display because, like yourself, I dislike the use of powerheads! The twist I am adding is an "Ocean Motion" 4-Way water distribution unit. I guess I am confused when I read about how many outputs for this loop since the OceanMotion unit will delay and/or rotate which of the returns get the water flow. My original design has A. (3) 1" returns on the left end and B. (3) 1" returns on the right end located just below the water's surface. In addition, I have C. (2) 1" returns on the left side of the overflow box and D. (2) 1" returns on the right side of the overflow box, again, just below the water's surface. Of course this totals the four locations (A,B,C & D) where the water will be distributed by the OM4. I can select an OceanMotion drum that services two of the four return locations at a time, (1/2, 2/3, 3/4 & 4/1) or one that utilizes each return opposite each other (1/4, 2/3) and then repeats. Do I have enough return outlets for the amount of water that will be pumped through the pipes via the Dart? I know if I had them all open all of the time I would have approximately 300GPH per return based oon (10) returns & 3000GPH, but I lose the "random" directional flow I am trying to achieve. If I opt for one of the above mentioned drums, I should have ±600GPH per return operating at any given time.... Too much?

If you can make any sense out of my post, you are more than the expert I consider you to be. If you need a diagram before shedding light, I completely understand and will provide an image. In any event, thank you for any input you might be able to provide. And, of course, that goes for all other's responses as well. Thank you.

Mike

[Anthony Calfo]

the 600 gph per 1" nozzle would not be too much flow at all... on the contrary, you will be surprised how diffused it is.

Yet you will not be getting that much flow per even under the best circumstances. From friction loss if not head as well, we simply cannot get the max mfg rated flow.

I really think you will be getting 400-500 gph per outlet from the above possible combinations (5-6 1" outlets on at any given time).

To test this a little bit... why don't you scavenge (new or used) a powerhead that is rated for 400-500 gph and modify its nozzle to have a 1" effluent stem. Then place that in the tank in various places (or just a deep sink for that matter with a plastic plant) to see how polyps/particles will react... and of course, if that seems adequate to you.

[Pez Vela]

Thank you Anthony. I appreciate the input!

mike