Check Valve?

Anyone have or use successfully a check valve on their return line(s)? Does such even exist? My returns are soft plumbed(vinyl tubing) and I have very little tolerance for backflow into my sump. I have battery backup and an emergency generator, but I'm always concerned if one of them failed I would have a real problem of flooding!

 

there are check valves for pvc, but im not sure if there are any for vinyl. check valves are faulty anyway because over time they can clog up and create more problems than the what they are supposed to help with.

 

drilling a hole in your tubing just below the normal water line in the display tank can stop most of the back siphon from occuring.

 

yes check valves are very nice especially when your return is under the water line quit a bit you can get nipple fittings to slip into a pvc check valve if you are currently using flex tube.

 

You should never ever rely on a check valve. They can and do fail, and usually at the worst possible moment.
A properly designed return and sump will not require a check valve or drilled holes which also require maintenance and fail just as often.
Place your returns so they are just slightly below the surface and only a very small, easily calculated amount of water returns to the sump and can be easily contained. You should always maintain that amount of room in your sumpa at all times. In my case its like 3.5 gallons in a 100G system and the sump is a 30G so I have plenty of freeboard or excess room.

 

Adding to this, a good height at which to have your return line is just under the top of the overflow's teeth. This way, you don't need any extra calculations.

 

Exactly, mine is 3/4" under the surface which is slightly less than the teeth on my internal overflow box.