Closed Loop

I thought of doing the same thing and had the same ideas. I have a dual return/overflow and so I was afraid it might mess up the flow and cause more noise, but I would think it wouldn't be a problem. the only problem i could think of was when I was doing maintanence to the sump and turned off the sump returns that it would affect my closed loop because there would still be water flowing into the overflow areas from the closed loop causing water to drain into the sump and causing a flood. I'll be interested to see what others say.

you will need to have a large screen on the intake(think pond strainer) to keep fish and snails out, being a closed loop if the pump stopped where would the water go, it wont leak unless the pump sprung a leak, very rare.

Brian

The intake screen and return outlet for a closed loop should both be in an area that can never go dry. The whole idea and efficiency of a closed loop is that it takes water directly from the tank and returns it directly to the tank. Think of a powerhead - it draws in and spits out from the same body of water. This eliminates the need to push water uphill as does a pump pulling water from a sump or overflow area and pushing it up to the tank. An overflow creates a new body of water so it is not the place to put the closed loop intake. If it were plumbed that way and the pump failed or the power went out the tank would back siphon all the water back through the output nozzle -> down into the sump, overflowing the sump right onto the floor.  And as has been stated, all the water flowing over through the teeth of an overflow is needed by the return pump. The whole idea of a closed loop is that it must be separate from the overflow.

Edited by Mark Peterson - November 16 2006 at 12:34am

Mark's description of the flood is exactly what happened to me.  I had the same "great idea" to put the intake of my closed loop into my overflow.  It looked great but it caused two floods (I'm a slow learner I guess) before I finally yanked it out of there and just put it in the main tank.  It was actually siphoning water from the closed loop output back into the sump through the overflow.  A couple of backflow valves would have probably fixed it, but by that time I was down to the last straw.  Since it has been in the main tank I haven't had any problems.

I was on Reefcast (see link on Melev's site) when I heard of Melev talking about some perforated black pvc that he used on a closed loop that virtually disappeared (See Episode 9).  Here is a link to it:

http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/8559/cid/2079

Anyway, after a while my intake was covered in coraline so it blends in.  I also rearranged the rock in my tank to help hide it from view.

Hope this helps.  Good Luck!

Edited by GARFVolunteer - November 16 2006 at 10:33pm

larger or more will lessen the impact if one of them starts to get plugged up.

Brian