Check Valve?
 

Is there such a thing as a Plastic Check valve? What would one use to help make sure his/her tank doesn't drain in the event of....pump/power failure?

(My 2 returns will be coming through the bottom of the tank and hiding in the LR.)

I ask because my fish probably won't like an empty tank.....And I don't want a full basement! :biggrin:

They do exist, but I hear they fail regularly. Most people have their return coming up over the side or thru the overflow, and drilling a small siphon break prevents back flow. In your case, check valves might be in order. Quickly before the power goes out/pump fails/etc.

Hello,

Yeah I'd not be able to sleep if my overflow runs up through the bottom of the tank, without any check valves or siphon breaks.

I'll trust siphon breaks more so than the check valves (which may not close 100%). But then you also may have siphon breaks with holes that gets clogged up. So you have to be careful in your design.

Titus

No worries...The tank is presently empty! :biggrin:

I am in the planning stages here....I want a good safe system, but I do want to use the return under the rock like that.

Siphon breaks are not an option this way. Well I guess they are but it would "break" with 2" of water in the tank.... :eek:

Where would I have a look for these Check Valves?

Another simple method, if your good at math, is to calculate the amount of water that will back flow into your sump and make sure you have that room left in case of an emergency. You can also fill your tank and unplug the return pump and watch how much water back flows.

Aquarium Illusion sells them. Be prepared to spend a lot as they (the checkvalves) are pricey as well as Aquarium Illusions. Best bet would be to look at JL's or give them a call.

You drill holes near the water surface for the syphon breaks.

I Had a look @ JL's.. I couldn't find any.

Perhaps I will head over to AI and have a look.

They can't be more that 10 bucks can they? I only need them in 1/2"

Jack, his returns don't go near the surface.

I bet they're a lot more than $10. And if they were $10, I wouldn't trust them.