Overflow help

[wright4941]

My tanks overflow has a single drain and a single return. A concern that has been preoccupying me lately is what will happen if somehow my drain gets clogged and the pump continues to pump thus creating an overflow. is there something that I can do to somehow failsafe this from being a possibility? Any help would be appreciated.

[Reef264]

You could cover your overflow box with a mesh screen, like me.You could get a pre-filter/Strainer for your overflow pipe intake.

[jamesdean3]

google herbie overflow and run the return up around the back of the tank. 100% safe and completly silent.

[uncleof6]

Make sure a plugged drain does not create an overflow. Usually what works best is an emergency backup drain, run in conjunction with a siphon. Works far better than an "open channel" durso type drain. Some use a small return section in their sump, but this leads to concerns with the pump running dry due to evaporation and an ATO failure.

[wright4941]

I'll check out the mesh screen idea and the herbie. Since my tank is already established and running I need something that can be added easily. Hopefully the herbie can done post set up like that. Thanks guys.,

[wright4941]

Ok after looking at the herbie it looks like you need two drain holes, but I only have one hole for the drain. So any other suggestions to cut down on the noise and make it safer.

[Ron Reefman]

Convert the smaller hole in your overflow (currently used for the return from the sump) into a second drain and use it as a backup. Then run the return from the sump over the back of the tank. This could be done even though your system is already up and running. Turn off the pump, drain the overflow box, remove the return line, replace it with the new drain line, install the new return from the sump over the back of the tank. If you prep materials in advance it shouldn't take too long.

This is part of what I did. And I run both of my drains wide open with only plastic strainers at the top. They run faster (more flow) than drains with a durso and they are 100% quiet. You just need to have enough return flow to the DT so the main drain stays under water and the 2nd drain is above the water unless the main drain clogs. Then the water level goes up and the 2nd drain picks up the excess and it will make a lot of noise... but then you'll know you have an issue.

[Playa-1]

My recommendation is to cover the entire overflow box with netting material to keep critters and debris out of the overflow. I would not screen over the drain pipe itself. Then just make a visual with your regular tank maintenance inspection to make sure that you don't have a build up of saltcreep or debris on the netting material.

[uncleof6]

Convert the smaller hole in your overflow (currently used for the return from the sump) into a second drain and use it as a backup. Then run the return from the sump over the back of the tank. This could be done even though your system is already up and running. Turn off the pump, drain the overflow box, remove the return line, replace it with the new drain line, install the new return from the sump over the back of the tank. If you prep materials in advance it shouldn't take too long.

This is exactly opposite from the way it should be. The smaller hole should always be the siphon, and the larger hole the emergency. This makes it virtually impossible under any possible scenario and normal circumstances, that the flow capacity of the emergency will be LESS than the flow capacity of the main siphon--save one: An occlusion in the emergency drain, following an occlusion in the siphon--but at this point nothing will prevent a flood, unless you have a second backup.

This is part of what I did. And I run both of my drains wide open with only plastic strainers at the top. They run faster (more flow) than drains with a durso and they are 100% quiet. You just need to have enough return flow to the DT so the main drain stays under water and the 2nd drain is above the water unless the main drain clogs. Then the water level goes up and the 2nd drain picks up the excess and it will make a lot of noise... but then you'll know you have an issue.


These systems work at any flow rate, (according to maximum values for a given pipe size,) within the range of the pipe size. From 1 gph up to umpteenth gph, without a a concern for the siphon not staying underwater. First by design (with elbows,) but even lacking this design convention, the adjustment of the water level in the overflow by the valve on the siphon line keeps the siphon line submerged, regardless of the return flow--if your return flow varies, then you have other issues that need to be dealt with.