closed loop drain..

[acpoweradapter]

Ok, I was going to put a cl in on my 40 gal but I was thinking about it and realized something. If the power goes out how do you keep the water from the main tank from draining out everywhere through one of the bottom holes?

[mnash]

I don't understand what you are saying. A closed loop shouldn't have any siphoning problems because it is a closed loop. The water comes out of the tank into a pipe, into the pump and then to another pipe that goes back to the tank. There shouldn't be anywhere for the water to go, unless your pump or plumbing leaks.

[Entropy]

I agree with mnash. A closed loop is exactly that. It is always full of water. If the power goes off, the water just stops moving, but the loop stays full of water. To achieve this the drain and return must always be under water (even when the power goes out).

[acpoweradapter]

Ok, so if the pump shuts off, it wont start spinning in reverse and letting water flow down the pipe?

[mnash]

It shouldn't but even if it does the water will not go anywhere because it is a closed system. If the intake "suck" line of the pump goes from the main tank to the pump, and then the output "blow" side of the pump goes from the pump to the main tank there is no way that water will or could possibly escape the system. (unless your pump or plumbing has a leak). A true closed loop system should have an external pump with no sump in its design. (you can obviously have a sump and a closed loop but that's not what I'm talking about)

[AZDesertRat]

A closed loop takes water out of the main tank, through a pump and back into the tank in a sealed piping system. There should not be any problems with power outages. Are you thinking about draining to the sump them pumping it back? If so thats not a closed loop thats a return pump. Closed loops are never exposed to atmosphere its sealed all the way.

[mnash]

Exactly. That was what I was trying to say. Thank you desert rat.