check valves

Hello. I have one question for you guys. You can see my sump/fuge on I Made This forum. This weekend I will change some plumbing from my fuge to 125 reef tank. I will have Mag 12 pushing water thru chiller to one overflow and Mag 9.5 puxhing water directly to second overflow. My question is do I need check valves for each line? I always had them but I,m not sure they are the must? I know they restrict flow a lot...Please let me know. Thanks!!!!!

 

I put one in my return line, but if I had to do it again I would have just left it out. If you leave your return just below the water line, you will have a siphon break and that is the best failsafe there is. Drilling holes in your return just below the water surface also works, but could be plugged by snails/algae.

Some check valves contain metal parts which could be detrimental to a reef system, so keep that in mind also.

 

What is that mean "leave your return just below the water line" Return line starts from return pump.... I'm confused...

 

The end of the return that goes up to the DT. If the end of it is at or above your water line in your DT, then it'll break siphon as soon as the pump stops and air hits the opening, so you don't need a check valve.

 

Yeah, I took my check valves out too. Just fill your sump to your preferred level, and make sure that the return heads in the display tank are just below (about 1") the surface. Then turn off your pumps, making sure you have a bailing bucket handy. Watch the water start to fill up in your sump. Hopefully the siphon breaks on your return lines before you have to start bailing water out of your sump (to prevent overflowing). If you do have to bail out water, keep doing so until eventually the water stops flowing. Then start up your pumps again, and draw a line on your sump at the new water level as "max fill". Or adjust your return lines so the siphon breaks sooner.

This is the only failsafe way to prevent a very wet floor. Check valves are mechanical, and like all mechanical devices, they eventually will fail.

 

Thank guys. I think finally I get it:-[