Mobile Bay Reef Keepers

I see posts regarding closed loop systems. Can someone please explain to me what that is?

Thanks

A closed loop takes the water directly from the tank, usually by the way of a bulkhead, to an external pump that dumps it right back into the tank, once again usually through another bulkhead.

I have one where i don't have any holes drilled in the tank so i have no bulkheads like mentioned above. I have a piece of black pvc in the tank that acts as the intake. It has a perferated cover on the end. The water flows up over the back of the tank and down to a reeflo dart pump that sits in my stand. Then it is pumped back up over the back of the tank and around the edge of the tank so i have outputs into the tank at 4 different spots.

Idealy you would just get your tank drilled so you don't have to pull the water up over the back, or have extra pipes in the tank. So in a closed loop the water never empties into a sump. The idea is to get greater waterflow without have tons of powerheads in the tank.

Thanks! That makes sense. I had never seen a setup like that but I see the advantages.

Here is a pic of the back of my 100 gallon with a closed loop. The two drains in the center go together and then to the pump which is returned over the top of the tank, in my case around the front of the tank. Mine didn't end up looking exactly like that but that is the idea. On my new tank I am going to have two 1.5" bulkheads and Spa-flex to reduce any noise from pump vibration and head pressure due to pvc fittings.

Here is how I set mine up, with a diagram and pics of the completed tank. In the design, CLS is "Closed Loop System". As Fishfood said, it is a way to get extra flow through your tank without going into a sump or having powerheads hanging in your tank.
http://home.comcast.net/~danleyjr/150setup.htm

Great example!

I only see one problem with that whole setup, is it yours ?

Yep, in operation for 18 months. It isn't perfect for sure, what do you see as a problem?

Well not so much as a problem with yours, just my bad luck with Mag pumps.

I'm building a tank room and moving the tank about 6 feet (which is almost as bad as moving cross country) and those Mags will be removed. They are noisy and don't move water like they should. I'll go with a Sequence and 4-way Oceans Motions, get more movement and less noise. Unfortunately I'll also have less money in my pocket.

Will a Sequence hold up in salt water, I remember them making pong pumps ?

Sure, that is who makes the Darts, Barracudas, and Hammerhead circulation pumps that many folks seem to be using.

Love my dart. I have a little salt creep from it but no noise at all and moves a ton of water.