Closed Loop, can I pull from within my overflow box?

S14_Silvia · 04-12-2005, 04:27 PM

I was thinking of doing a CL system similar to the one on melev's reef

http://www.melevsreef.com/closedloop.html

I was wondering if I can have my supply line hidden in my AGA overflow box, or would this cause problems with air bubbles getting in the system. Also as for piping size I will be using a mag 7 with a 3/4" SCWD so would there be any point to having bigger than 3/4' piping if I am limited by the 3/4" SCWD. Or can I use 1" for the supply and 3/4" for the return. And lastly if there any place locally to get black fittings, I would like to avoid having white fittings showing in the tank. Ok one more thing, what would be my best choice for placement of the returns. In each corner, in the middle, one on the side and one in the middle?

bjmd22 · 04-12-2005, 04:54 PM

You can pull from anywhere you like. However your overflow is connected to your sump which is below your tank, and your intake will likely be lower than your outflow, so if your pump quits(electricity outage) you may endup siphoning from your tank and get a wet floor!

S14_Silvia · 04-12-2005, 05:16 PM

I don't mean from the standpipe itself. What I meant was can I have the supply line hidden within my AGA overflow. That way you will not see the pipe in the tank, only the 2 returns.

Twins Guy · 04-12-2005, 05:51 PM

hey kevin-
you can do this...thing you have to watch for is whether the teeth on the overflow box can keep up with the flow of the closed-loop pump plus the return pump. if there is more water flying in there and "waterfalling" you might notice some air bubbles getting sucked into the closed-loop or more noise from the drain line (if it takes on more air bubbles). greg did this on his 58 with what amounted to ~1000gph (right greg?) between a couple of iwaki pumps (one return and one CL).

frictional losses due to 3/4" pipe vs 1" should be negligible on such a small (length of pipe wise) CL system. go ahead and prove me wrong though. i would prolly just stick with 3/4" gray schedule 80 pvc from indelco in st louis park (stop in or call ahead to the city desk-but know what you're looking for). i'm unaware of a source for black pvc in that size.

as far as CL return outlets i would position them away from other sources of flow-just so you hit some different angles and "spread the wealth".
tg

Tutmos · 04-12-2005, 06:31 PM

Couple questions, don't you want to skim the water from your overflow instead of mixing a good deal of it back into an emulsion and sending it back into the tank?

Also, assuming this is just for flow is there any reason not to just use a Tunze or two since the GPH numbers are actually larger with no piping, floods, etc.? Cost is probably about the same I'd assume.

Kevin

S14_Silvia · 04-12-2005, 06:44 PM

Quote:

Originally Posted by Twins Guy

hey kevin-
you can do this...thing you have to watch for is whether the teeth on the overflow box can keep up with the flow of the closed-loop pump plus the return pump. if there is more water flying in there and "waterfalling" you might notice some air bubbles getting sucked into the closed-loop or more noise from the drain line (if it takes on more air bubbles). greg did this on his 58 with what amounted to ~1000gph (right greg?) between a couple of iwaki pumps (one return and one CL).

frictional losses due to 3/4" pipe vs 1" should be negligible on such a small (length of pipe wise) CL system. go ahead and prove me wrong though. i would prolly just stick with 3/4" gray schedule 80 pvc from indelco in st louis park (stop in or call ahead to the city desk-but know what you're looking for). i'm unaware of a source for black pvc in that size.

as far as CL return outlets i would position them away from other sources of flow-just so you hit some different angles and "spread the wealth".
tg

my overflow can handle 600 GPH and my return pump is pushing about 550GPH so with a CL around 450GPH I would be exceeding what my overflow can handle, right? As for air bubbles I was planning on putting the inlet way towards the bottom of the overflow to try to avoid excessive bubbles being introduced to the CL. If worse comes to worse I can have the intake in the tank, but it's worth a shot trying to hide it in the overflow. And thanks for the info on indelco, that's right by my girlfriends house and I could probably pick up some piping this weekend.

BTW, does anyone have a SCWD they're not using, preferably new. I try to save $ whenever I can especially when I am broke but still manage to scrounge up $ for the tank........priorities

S14_Silvia · 04-12-2005, 07:55 PM

Quote:

Originally Posted by Tutmos

Couple questions, don't you want to skim the water from your overflow instead of mixing a good deal of it back into an emulsion and sending it back into the tank?

Also, assuming this is just for flow is there any reason not to just use a Tunze or two since the GPH numbers are actually larger with no piping, floods, etc.? Cost is probably about the same I'd assume.

Kevin

It is just for flow and since I've already got the pump and a SCWD is around $40 it would be a lot more $ to get a couple tunze's.

Clownnut · 04-12-2005, 08:07 PM

scwd. ebay. 28.95 free shippin/ i just bough 7 of them week ago.
the bigger gph u pump get the fast it switchs. so i think redsea wavecontrol+ 2 seio(i heard 820 can use with it).

Lars · 04-13-2005, 12:32 AM

BTW - this does not work if you have two overflow boxes. It made sense on paper lol. But half the water you pull out of the box (statically) goes to the other box. So it ended up draining the overflow box pretty quickly when I tried it.

Lars.

Fahz · 04-13-2005, 10:28 AM

Here's a few notes white PVC can be colored black with a Sanford king size marker and it's no problem with toxins.

I'm running a mag 9.5 on a Melev CL and bigger size PVC is better and still may make noise. I made my second one with ballvalves on the in and out flow to stop pump cavatation. The cavatation sounds like ballbearings rolling.

Fahz

the_colonel · 04-13-2005, 10:41 AM

Besides Fahz's idea of using a black Sanford king size marker, you can just coat all the white PVC that will be in your tank with purple PVC primer. Looks kinda like coraline until the coraline comes in.

trodder · 04-13-2005, 10:46 AM

Do you have 2 holes in your over flow or just one? I actually have Gregs old 58 and I am doing a closed loop from the "return" hole. There is a whole for the main drain and one that is meant for your return line but I am using it for the drain for my closed loop. The pump is plumbed under the tank and not in the overflow box. The problem with my set-up is if I loose power on my return pump (downstairs) then I am risking burning out the mak4 that I am using upstairs for the closed loop, because the source of the water is dependant on water flowing into the overflow box which won't happen if I loose my main return pump. I did something that might fix that scenario but I am too afraid to test it. What I did was I had one durso for the main drain and one for the closed loop. The pipe for the closed loop comes down further than the main drain durso in hopes that it will allow enough water on the bottom of the overflow at all times to keep the pump from burning out. The intake for that durso is a capped pipe with a bunch of holes drilled all over the bottom (to create a strainer) this also eliminated the micro bubbles I was getting at first. I was getting them originally because I did the intake part of the durso just like the main drain intake and that was making holes/slots almost all the way up and down the intake pipe of the durso. What would happen that way is though I got the level in my overflow box to come up and remain level just below the teeth there was just enough water crashing in to make bubbles go deep enough in the box to get sucked into closed loop. As soon as I isolated the intake to the bottom inch or two of the overflow box the microbubbles stop. I hope I am making sense if not let me know I will try to get pics or explain better.