Check valve.. to use or not to use

[vcnt]

If I am running an over-the-back return with to 90s would I need a check valve? I'm just guessing but the loc-line would probably be about 2-4inches deep under waterline

 

[EeyoreIsMySpiritAnimal]

If I am running an over-the-back return with to 90s would I need a check valve? I'm just guessing but the loc-line would probably be about 2-4inches deep under waterline

Check valves WILL fail.
Add a siphon break in the loc line, and test to make sure your sump can handle the amount of water that is siphoned before the break stops it.

 

[vcnt]

Check valves WILL fail.
Add a siphon break in the loc line, and test to make sure your sump can handle the amount of water that is siphoned before the break stops it.

How could I test it without testing it (really dumb question im sorry)

 

[Sirlagzalott]

Check valves WILL fail.
Add a siphon break in the loc line, and test to make sure your sump can handle the amount of water that is siphoned before the break stops it.

Definable a potential point of failure. Agree that a siphon break is the only true way to be sure. Also ideally make sure your sump can handle the extra water if your return shuts off.

 

[vcnt]

How to do a siphon break?

 

[EeyoreIsMySpiritAnimal]

Do a bit of research...

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.reef2reef.com/threads/siphon-break-in-loc-lines.443920/&ved=2ahUKEwj-6pD_hIuFAxUM5MkDHdByC3EQFnoECBEQAQ&usg=AOvVaw2OBCEM8kLt2XLveaU0H4sQ

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=http://www.reefcentral.com/forums/showthread.php%3Ft%3D1269767&ved=2ahUKEwj-6pD_hIuFAxUM5MkDHdByC3EQFnoECBQQAQ&usg=AOvVaw3eOJtW-LXVx7y0hz_vG6N1

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://forums.saltwaterfish.com/threads/return-line-siphon-break.368403/&ved=2ahUKEwj-6pD_hIuFAxUM5MkDHdByC3EQFnoECA4QAQ&usg=AOvVaw2EGUIS0apwpQPlIPvOJOXZ

 

[Sirlagzalott]

Drill a small hole in the return line where you want the water to stop siphoning. Or you can let it drain until the return line is exposed.

 

[RocketEngineer]

Because no one else did, here is WHY they fail:

Reef tanks entail growing more than just the fish and corals we introduce. They are a small biosphere. As such, we tend to have sponges, feather dusters, and other fauna appear without our input. Should a sponge or feather duster grow on the valve, it will prevent it from sealing. No amount of maintenance is likely to prevent this from happening. It’s therefore best to avoid using check valves and instead rely on other methods of avoiding water overflowing.

 

[kilnakorr]

Because no one else did, here is WHY they fail:

Reef tanks entail growing more than just the fish and corals we introduce. They are a small biosphere. As such, we tend to have sponges, feather dusters, and other fauna appear without our input. Should a sponge or feather duster grow on the valve, it will prevent it from sealing. No amount of maintenance is likely to prevent this from happening. It’s therefore best to avoid using check valves and instead rely on other methods of avoiding water overflowing.

Which could also happen using a siphon break, if not maintained.