Plumbing/SCWD/Flow Questions on 90 AGA RR

[pmcustom]

I am going to upgrade my 90gal setup from a Mag 12 with 3/4" return plumbing to a PCX55 with prob 1.25 plumbing tee'd to 3/4" eductors. My question is about flow. I'm not going to alter the setup by using both holes as drains because I'm going to run a closed loop for circulation, and I'm worried about having too much flow for the 1" drain and/or overflow slots. Do you think the PCX55 (prob about 1k gph without figuring the eductors) will be too much? I also would like to add a SCWD, in which case some extra flow would be perfect since it will rob a lot of it. Thanks for the help.

[Blown 346]

I have a 90 and have 1 1" drain, and it is good for about 600 GPH. I also have a closed loop, but the drain wont have any affect on the closed loop or vice a versa. The only thing the drain will have a ffect on is the retrun pump back to the tank.

On my closed loop I have 1" PVC with a Quiet One 6000 for a pump. Iy has a total GPH of 1506 and 1300 with all my plumbing and my SCWD.
I actually thing that I could use more flow in certain areas of my tank, I think you will be fine with what you have. You should have enough flow to kep any coral you want depending on where you place them and where the retrun lines are.

[sjm817]

You had the Mag12 throttled WAY back with the 3/4" plumbing. You want ~ 3 - 5X display volume which is 270 - 450 GPH. I think both of those pumps are too big for a return pump.

[pmcustom]

I know the plumbing is wrong, that's why I'm upgrading, but 3-5x is nowhere near enough flow for a 90gal tank. I figured I'd use the PCX55 for now, and then double it when I can add a closed-loop in the future.

[sjm817]

<a href=showthread.php?s=&postid=6631889#post6631889 target=_blank>Originally posted</a> by pmcustom
I know the plumbing is wrong, that's why I'm upgrading, but 3-5x is nowhere near enough flow for a 90gal tank. I figured I'd use the PCX55 for now, and then double it when I can add a closed-loop in the future.
Correct. 3 -5 x is not enough total display flow, but it is enough for display->sump flow. Not sure how much the SCWD will cut back the flow. It really kills a Mag pump, but the PCX should handle the head pressure much better.

[pmcustom]

OK, I wasn't sure what you meant. I think I will run the SCWD with two 3/4" eductors then. There will be a lot of head pressure, but the pump is high pressure and it may be too much flow anyway for the overflow. Thanks.

[sjm817]

Not sure how well that will work. The eductors need lots of pressure to work, but the SCWD will be working against you there. I'm not familiar enough with eductors to really say though.

[pmcustom]

The PCX55 will pump to 28ft, so I doubt that will be a problem. Plus, the reduced flow can't hurt since it's going through a 1" drain and the sump.

[sjm817]

Lets us know how it works out!

[pmcustom]

It will be a while...I just got the pump, so now I have to build the sump (it's already designed) and plumb everything. I'll try and post an update.