Closed loop/return pump together

[Fishbulb2]

Hey guys,
Planning on redoing my plumbing. Shooting for about 3-5X turnover through my sump and would like about 10-20X turnover in the tank. This is what i've come up with to incorporate the same pump for a closed loop (sorta) and my return pump.
Can anyone see something wrong with this? I basically have one outlet for the mag pump that will go to the scwd. Then there are two intakes, one that is fed from the closed loop drain and the other is just straight from the sump. This way I can use a larger than recommended sump pump but adjust how much water goes through the sump and how much comes through the closed loop directly to the pump and bypassing the skimmer, fuge, ect. The valve will control the ratio between the two. With the valve closed, all the circulation is through the sump. With the valve open, I suspect a lot of the water will flow directly to the pump. I suspect in the case of a power outage, anti siphon holes will prevent the tank from draining into the sump. Then when the power turns back on, the pump will draw from the sump and suck the air out of the closed loop intake.
Will this work?
FB

http://reefcentral.com/gallery/data/500/120725pump.jpg

[Harold Edwards]

I was just thinking about this the other day. I would like to do this on my next tank. my reason for doing this would be to have one pump running instead of two. Also to save on some electric.
I was planning on a 75 gallon tank. what size tank are you planning?
I thank this will work, Hope someone has done it already and has some pictures

[reefez]

If you have your return plumbed into a closed loop line then if you lost power or turned the power off you will have a flood through the sump.

[Fishbulb2]

I think it will work too. I'm going to be trying it on a 40 but I think it could obviously scale up.

reefez,
I don't think it will overflow the sump because I can just put anti-siphon holes in the intake. So it's not truly a closed loop but quite similar. So water would drain down to the sump but only to the anti siphon holes. Then when the pump turns back on. It would fill the tank back up above the anti siphon holes and most of the water will flow through the regular overflow and through the sump until the pump has had a chance to vacate all of the air from the CL intake.

Alternatively, you could also just add a pvc check valve

http://www.plumbingsupply.com/pvccheck.html

for like $10 which would preven any water whatsoever from flowing back into the sump during a power outage. Then when power goes out, all of the lines stay filled, and when power is resumed the valve effortlessly reopens.

I'm very surprised no one else has tried this. I think i'll hook it up this weekend. Please though, if anyone has anymore input i'd really want to hear. I don't want to have to redo the plumbing in the future.
FB

[rickh]

Fishbulb2---how about giving us a bigger picture. I am a old guy:cool:

[Fishbulb2]

I would love too. Having a hard time with uploading pics and working and such. I'll try again.
FB

[Fishbulb2]

Ok hopefully this is bigger. I hope so. THe pipe with the valve will get the input directly from the tank, thus bypassing the sump. The large rising pipe with the union is the return which will ultimately goes to the SCWD.

let me know if it's clear.
FB

http://reefcentral.com/gallery/data/500/120725pump2.jpg

[jmuscat2]

Do not trust check valves. They will fail when you need them most. I found this out the hard way.

[Tang Salad]

One issue to consider is the flow-rate of your overflow. It will need to handle many, many more GPH if it's also feeding the 'closed' loop. This could lead to bubble problems.

[Fishbulb2]

Thanks for the tip Tang,
I'm considering adding a strained intake like melev uses on his smaller closed loops, which should entirely eliminate the possibility of microbubbles from the "CL" intake since it is all fully submerged. http://www.melevsreef.com/closedloop.html However, I also wanted to reduce how much plumbing and PH were visible in the tank so I think I will first try to plumb directly from the overflow. I have two separate drains from the overflow box. I will need to make one much shorter than the other and feed it to the 'CL' with the ballvalve. That way the intake should always be submerged.
FB