Splitting Return Pump Multiple Ways - Need Help

[forddna]

I have the setup in my signature. I'm purchasing an MRC 36" reef sump, which has a built in refugium section that is partitioned off and you have to feed it with a pump. Ideally, I'd like to have 400-500gph through that section. (it then overflows into the return pump section, but standing water in the sump doesn't go into it unless fed by a pump)

My second consideration is my skimmer. The pump is rated at 660gph.

Now, here's what I already own that I can work with, or trade for something different:

Mag 18 (1800gph)
Mag 12 (1200gph)
Mag 9.5 (950gph)

I don't want too much return flow so that I'm returning too much unskimmed water. The return pump will be split two ways to feed the two tanks. I'd like to split it a third way to feed the refugium.

My question is, would it be beneficial to split it 4 ways and have the 4th just loop back into the sump so that the actual amount leaving the sump is that much less? My reasoning for this is that I'm afraid if I get a smaller pump and split it 3 ways and stay under my 660gph leaving the tank, it'll be really weak flow going back to the main tanks. Is that even a valid concern?

 

[powderhound]

Why not T off your drain line into the refugium, can be dialed in with a gate valve. Depending on how much flow you want thru the refuge. Would allow a smaller pump used to return to the tank, and if you want more flow to either the skimmer or refugium just dial it up or down .

 

[forddna]

If I did that, that water going to the refugium wouldn't get skimmed. Hmm..

 

[forddna]

I'm also not completely sold on using using the skimmer I have (it came with the setup). I may seek out something better and intentionally go with something with more gph.

 

[powderhound]

Not all the water that goes to your skimmer section now is being skimmed. Only a portion of it is. With enough turnover that percentage skimmed goes up, but Teeing off to the refugium isnt going to change the amount of water skimmed by that much. Depending on what you put in your refuge(Cheato) it will pull nutrients out of the water.

 

[ca1ore]

Not all the water that goes to your skimmer section now is being skimmed.

True. Would be possible, I suppose to feed a skimmer directly from the drain, but even if one did that, seems highly doubtful that all the removable organics get stripped in just a single pass anyhow. Matching skimmer processing volume with sump turnover always seemed pointless to me,

 

[forddna]

Here's a pic of the sump so you get an idea. Skimmer goes in the far right, and there's a small partition in the back that allows water to flow to the back left (return pump section). The front left is the refugium, which is completely closed off, except to be fed by a pump into that bulkhead, and then it overflows to the back.

My purpose for returning some water right back into the sump is just so that there is less actually leaving the sump than what these bigger-than-I-need pumps would pump back up. My way of throttling it down, in a sense.