Overflow water level issue

[3 tanks]

The water level in my 75-gallon reef tank overflow keeps receding and refilling over and over. Any ideas what could be wrong? Attaching a video of the problem. Thanks much!

 

[CodyRVA]

Have you tried adjusting your gate valve, assuming you have one?

 

[AZDesertRat]

What standpipe do you have? Does it have a way to feed air into the pipe to get better flow? If it is a single overflow it should not have a valve on it as that is a guaranteed flood.

 

[3 tanks]

Have you tried adjusting your gate valve, assuming you have one?

We don't have a gate valve. Thanks though.

 

[3 tanks]

What standpipe do you have? Does it have a way to feed air into the pipe to get better flow? If it is a single overflow it should not have a valve on it as that is a guaranteed flood.

It has no valve. It's an older tank. Maybe we should try cleaning it up a bit?

 

[BoneXriffic]

Possible air bubble hung up?

 

[AZDesertRat]

OK. on my computer now so can see the pics.
Take a piece of clear vinyl airline tubing 12-18" long and slowly feed one end down into the hole on the elbow of your standpipe. Slowly is key. You will probably get 1-2" in it and the flow will become steady and take off like crazy while at the same time the standpipe will become almsot totally silent. Tape or tie up the loose end of the tubing so it hangs over the back a little bit or along the trim so it doesn't fall in the water.
Introducing just the perfect amount of air into the overflow gives you a smooth laminar flow and stops the gulping for air.

 

[BoneXriffic]

OK. on my computer now so can see the pics.
Take a piece of clear vinyl airline tubing 12-18" long and slowly feed one end down into the hole on the elbow of your standpipe. Slowly is key. You will probably get 1-2" in it and the flow will become steady and take off like crazy while at the same time the standpipe will become almsot totally silent. Tape or tie up the loose end of the tubing so it hangs over the back a little bit or along the trim so it doesn't fall in the water.
Introducing just the perfect amount of air into the overflow gives you a smooth laminar flow and stops the gulping for air.

Thats the same over flow is mine it has a cage on the elbow...but it has a hole on top to vent....maybe salt creep plugged it?

 

[AZDesertRat]

Stick the piece of airline tubing down inside the hole until the standpipe becomes steady and quiet, works every time. The hole doesn't let the water and air mix, when you inject the air below the surface it is night and day different.

 

[3 tanks]

Thats the same over flow is mine it has a cage on the elbow...but it has a hole on top to vent....maybe salt creep plugged it?

Wow. Great advice. Will try this tonight and let you know if it helped. Thank you SO much.

 

[3 tanks]

Thank you SOOOO very much. The trick with the tubing worked and the levels are steady now. We really appreciate your advice!

 

[AZDesertRat]

Glad to help. Someone years ago shared that trick with me and I'm just passing it on.