Stop DT from overflowing after power outage

[Will_WhatIsThis]

I’m planning out my first sump and I’m very paranoid about floods. My question is: how do you stop your return pump from pumping all the water back into your tank from your sump after a power outage, and overfilling your tank? I read something about drilling a hole just below the water surface of the return line, but I’m a little confused on that. Can someone please dumb that down a bit for me?

 

[Mical]

Drilling a small hole in return line just below water level will prevent a "back siphon" into your sump, causing that to overflow if you were to lose power. If you have a power outage your return pump will shut off and they'll be NO water pumped into display tank.

 

[SMSREEF]

There will not be any water added in a power outage, the water is just in a different place. When the power comes back on it will stabilize where things were set before the outage.

The only way water would flow into tank from the sump in a power outage is if your sump is above the tank and the plumbing creates a siphon taking all water from sump to tank.

usually though, the sump is under the tank so this is reversed and water from tank is siphoned down into the sump. At least until air gets into the line.

This is why my return line is planned to be just below the surface of the display tank. After about 4-5 gallons siphons down, air gets in the line and breaks the siphon.

I make sure I have enough room for all the water when power goes off by testing it. If I am too close to sump overflowing, I raise the return a little higher to the surface of the display tank so less water siphons down.

when power comes back on, the extra water in sump is pumped back up into display and everything is back to normal.

 

[Will_WhatIsThis]

Thanks for explaining. Im really overthinking things.

 

[lilgrounchuck]

Not overthinking when it comes to safety and damage mitigation. You shouldn't worry about it flooding your tank when the power comes back on, but you could flood your tank if your drain gets blocked up. What you'll want to do is find a good balance to where your pump stops and the sump doesn't flood, as well as if your drain clogs up the return chamber of the sump can drain completely without flooding the tank. Once you find those max levels, mark them and don't go over them and you'll be fine.

 

[Mical]

Hopefully this will explain it easier ->

 

[Bacon505]

you mean water overflowing your sump and not your tank? There will be back drain from your return if it doesnt have a check valve

 

[Will_WhatIsThis]

Thanks for all the help everyone! This is really giving me the conifidence I need to finally get myself a sump.

 

[fishguy242]

best advice i can give after all infomed up and running pull the plug make sure everything holds properly happy reefing

 

[Will_WhatIsThis]

Thanks I’ll try my best!

 

[W1ngz]

you mean water overflowing your sump and not your tank? There will be back drain from your return if it doesnt have a check valve

This is incorrect. Place the return nozzle high enough so it cant siphon more than a gallon or two, or drill a siphon break hole. Check valves are prone to sticking and clogging. They have other benefits, but safety isn't one of them.