Closed Loop Setup

[reef master jon]

I’m setting up a closed loop connection with a MAG 9 pump on my 75gal tank. I am going to drill two holes for the water to flow through, and my question is , should i drill a third hole for the intake, or use PVC pipes over the top of the tank to suck water out?

here are some examples

http://reefcentral.com/gallery/showphoto.php?photo=264801[/IMG]

[crvz]

you'd want to drill an intake, the mag 9 would not self prime in the even of a power failure if you have a PVC tube pulling water over the top. In any case, a mag 9 isnt really that powerful of a pump for a CLS to begin with, and Iwouldnt expect a whole lot of flow out of it. I suppose it would suffice for a 75, but I figure if you're going to do a CLS you may as well over do it (more holes, quality pressure rated pump, etc.).

[THEUNION1]

<a href=showthread.php?s=&postid=14129375#post14129375 target=_blank>Originally posted</a> by crvz
you'd want to drill an intake, the mag 9 would not self prime in the even of a power failure if you have a PVC tube pulling water over the top. In any case, a mag 9 isnt really that powerful of a pump for a CLS to begin with, and Iwouldnt expect a whole lot of flow out of it. I suppose it would suffice for a 75, but I figure if you're going to do a CLS you may as well over do it (more holes, quality pressure rated pump, etc.).
What would you recommend for a pump?

[reef master jon]

ok, i just dont want any of my fish being sucked up in the pump if i drilled a hole for the intake. i feel that the PVC pipes might be a lil safer dont you think? also i have a quetions, i also have another mag 9.5 for the return from my refuge, and overflow box rated 600mpg. is this pump (mag 9) best fit for this setup? what would up sugguest?

[mfinn]

<a href=showthread.php?s=&postid=14129375#post14129375 target=_blank>Originally posted</a> by crvz
you'd want to drill an intake, the mag 9 would not self prime in the even of a power failure if you have a PVC tube pulling water over the top.

While drilling a hole for the intake is the better option, if the over the top pvc suction is done right, it will not lose the prime.
I've had a over the top pvc closed loop on my 240 setup for about 2-1/2 years, had 8-9 power failures and never had a problem.
As long as the intake is far enough down in the tank, you will be fine.

I used a mag 12 for a closed loop on a 40 gallon tank and the flow was great. It was a over the top CL also.

When you drill and use a bulkhead in a tank for the suction side of a pump you can make strainers that won't suck fish into them.
A friend made one out of acrylic. It was shaped like a small box that had many holes in it and was siliconed to the back wall of the tank.

[kdc527]

I have a mag 9 return on my system with a 600 gph overflow I just have the pump balled back with a valve works fine

[reef master jon]

where should i place the intake bulkhead? over or under the two return bulkheads? or does it matter. and should i use a bigger pump for my return from the refuge? once again i have (600mpg overflow box current pump is a MAG 9.5 ) also i drilled two return holes and placed bulkheads on the upper edge part of the tank.

[crvz]

Good point about the over-the-top CLS intake, mfinn.

<a href=showthread.php?s=&postid=14129384#post14129384 target=_blank>Originally posted</a> by THEUNION1
What would you recommend for a pump?

I'm not up on good external pumps, but I know the mag drive line wouldnt be in the list.

<a href=showthread.php?s=&postid=14129466#post14129466 target=_blank>Originally posted</a> by reef master jon
ok, i just dont want any of my fish being sucked up in the pump if i drilled a hole for the intake. i feel that the PVC pipes might be a lil safer dont you think? also i have a quetions, i also have another mag 9.5 for the return from my refuge, and overflow box rated 600mpg. is this pump (mag 9) best fit for this setup? what would up sugguest?

As pointed out, a strainer would eliminate (or drastically reduce) that risk. I don't think PVC would be any safer, you'd still want a strainer on that.

I use a mag 9.5 on my 150 for a return, and it's fine. You could use that pump, but have a good gate valve plumbed on the return plumbing to back it down a bit as needed.

<a href=showthread.php?s=&postid=14129870#post14129870 target=_blank>Originally posted</a> by reef master jon
where should i place the intake bulkhead? over or under the two return bulkheads? or does it matter. and should i use a bigger pump for my return from the refuge? once again i have (600mpg overflow box current pump is a MAG 9.5 ) also i drilled two return holes and placed bulkheads on the upper edge part of the tank.

It shouldnt matter where to put the intake for the CLS, but higher up to keep from sucking in sand.

But your also talking about the return pump, right? So you have two mag 9.5 pumps for this tank? And when you say you drilled holes for the return, are these at risk of draining the tank a certain amount when you lose power?

[mfinn]

I'd place the intake bulkhead dead center in the back wall.

I only went with a over the top CL, because my tank was shipped from the east coast to the west coast and I was a little paranoid about shipping a tank with holes drilled in the back wall.


One more point on the over the top pvc suction tube, I made mine so that it went more than half way into the tank. I put a cap on the end. I used my chop saw and cut slices into the pipe for a total of about 6-7 inches. I did several water tests to see how strong the suction was, as I wanted to keep small fishes like mandarines.
As luck would have it, my rose anemones have decided they like this end of my tank and that is where they are now. They split quite often and the babies end up very close if not on the suction tube of the closed loop and I haven't had a problem with them getting sucked into it.
My closed loop pump is a Poseidon P-4 and I figure I get about 1000 gph with it.

[mfinn]

I'd consider doing 2 holes for the suction

[reef master jon]

CRVZ,

yes i know the higher the bulkheads for the return form refuge is better because of back flow ( draining) . i understand that, and i think that my refuge could handle the water amount. i think

[crvz]

<a href=showthread.php?s=&postid=14130848#post14130848 target=_blank>Originally posted</a> by reef master jon
...i think

I'd make certain before relying on it. ;)

[reef master jon]

thanks for the information, i am waiting for my glass cuttter for gl*******.com and ill let you know what happens....