closed loop (with scwd) advice

spineshank385 · #1 03/03/2006, 05:28 PM

i have a closed loop plumped into my tank currently, using 1" PVC. I'm using a mag 7 to circulate water, however, i'm not getting very much velocity. Is this something to worry about, or should i just let it go, since combining with my mag 5 return mpump, i have 5-600 gph turnover on my 29g tank.

OR, should i reduce the size of the return plumbing for the closed loop to 3/4" with 1/2" outlets on either side? (there are 2 outlets both pointing toward the middle of the tank on either side).

i would like some suggestions here. thanks

bdbernard · #2 03/03/2006, 06:46 PM

I am currently running a little giant pump rated at 600-700 gph through a scwd to a 30g tank. The 3/4" water line out of the pump to the scwd alows for more than enough flow rate. I have found that the scwd alternates about every 7 seconds with good velocity on this setup. I dont know if this helps, but mine seems to work great.

mr pink floyd · #3 03/03/2006, 08:34 PM

im gonna run a mag 7 fro mmy 10 gal sump to my 29, gonna run it maybe 1.5-2 feet over, and up 6 inches, over the lip then down into the tank, put on a t or 45 and angle it twords front corners, i think you maybe be pumping too far or something

spineshank385 · #4 03/03/2006, 08:48 PM

theres MAYBE 1 foot of head pressure

i'm leaning towards the 1" return piping being too large for a good amount of water velocity...

when i say velocity, i mean speed.....i'm sure there is PLENTY of flow, but its not real fast.

escape2theocean · #5 03/03/2006, 11:32 PM

You could also upgrade the pump, of course. Thats what I idid with my closed loop. Originally I had a mag7 but I was disappointed with the flow/velocity so I went to a mag9. I had an extra mag9 so I used it but if I were to buy a new pump it would prob be a mag12.

bassnman11 · #6 03/04/2006, 01:00 AM

Get some 1 inch to 3/4 slip pvc bushings and some 3/4 to 1/2 of the same. You can slip them in your line(no glue) and see which one gives the desired velocity. I went from 3/4 down to 1/2 in 4 outlets to get what I wanted.

ddenham · #7 03/04/2006, 10:01 AM

IMO drop the SCWD. A SCWD will knock the flow down way too much for a Mag 7 (or probably any mag for that matter)

orlenz · #8 03/04/2006, 11:26 AM

I would lose the SCWD also, Youll get much more flow without it.

kellymm7149 · #9 03/05/2006, 08:40 AM

i run a mag12 with mine i think its best to use 3/4" hose you don,t want any sharp bends like you get with pvc + elbows it alone will reduce your flow

Simms142 · #10 03/05/2006, 10:42 AM

go to oceansmotions.com and order a 2 way and use that instead of a scwd. You will not regret it and they are awesome.

drparker · #11 03/05/2006, 01:50 PM

I'm with Brian.

I trashed my SCWD and put in the Ocean Motions Squirt. You don't loose any flow like you do with a SCWD and switching time is a constant no matter waht flow rate your pushing.

He's got a pic gallery that will give you all kinds of ideas, I upgraded from the two outputs of the SCWD to the 4 of the Squirt. My corals love it.

Drew