Reef ready tank overflow clogging

[Silly clownfish]

I have a 75 g reef ready -black dual wall overflow on the left side back has 2 small vertical series of slits - one near the top and one about a third of the way up from the bottom. the tank has been running for about 9 years with a Herbie overflow. In the last few months I have been having issue with the black plastic overflow clogging and the water in the tank backing up until it flows off per the top of the plastic into the overflow. The Herbie pipes are operating fine, the water level in the overflow chamber stays where I want it. It is the water level in the main tank area that rises.

I have had more hair algae than normal recently, but I don’t recall having it stop up the overflow like this before. Any thoughts? I don’t know what is between the 2 layers of black plastics that form the overflow.

i am not concerned about the tank overflowing as the top of the overflow is enough below the rim, but it is causing problems with my ATO.

 

[kzenoni]

While battling algae in my tanks the slots would slowly get blocked. I used brushes to clean them weekly. If I missed a week the display water level would rise. Hope this helps

 

[vetteguy53081]

I have a 75 g reef ready -black dual wall overflow on the left side back has 2 small vertical series of slits - one near the top and one about a third of the way up from the bottom. the tank has been running for about 9 years with a Herbie overflow. In the last few months I have been having issue with the black plastic overflow clogging and the water in the tank backing up until it flows off per the top of the plastic into the overflow. The Herbie pipes are operating fine, the water level in the overflow chamber stays where I want it. It is the water level in the main tank area that rises.

I have had more hair algae than normal recently, but I don’t recall having it stop up the overflow like this before. Any thoughts? I don’t know what is between the 2 layers of black plastics that form the overflow.

i am not concerned about the tank overflowing as the top of the overflow is enough below the rim, but it is causing problems with my ATO.

Check the trap going into overflow pipe and if no trap, take a thin measuring tape and run down the piping like a plumbers fish tape to loosen any obstructions.

 

[EeyoreIsMySpiritAnimal]

Check the trap going into overflow pipe and if no trap, take a thin measuring tape and run down the piping like a plumbers fish tape to loosen any obstructions.

???

 

[EeyoreIsMySpiritAnimal]

While battling algae in my tanks the slots would slowly get blocked. I used brushes to clean them weekly. If I missed a week the display water level would rise. Hope this helps

Ditto. If the lower intake slots get clogged, the water level in the tank will rise.