Tank Overflowing

[kara13]

Two nights ago, my tank overflowed from the top. I had a Apex COR 15.

Yesterday I took everything in tank apart and checked for blockages and cleaned it. Put in a new simple Sicce pump. The tank will still overflow if I let it run.

The overflow area in the tank is now filling all the way with water then emptying below the area of the pipes. I'm not sure how to describe it, so I have a video.

Fish Tank | fish tank - SD 480p
Fish Tank | fish tank - SD 480p

I'm not sure what to do next and would appreciate any suggestions. Thanks!!

 

[Timfish]

The water in the overflow is starting a siphon when it gets to the top of the Durso overflow letting it quickly drain. When the water level drops below the intake it sucks in a bunch of air stopping the siphon and making the gurgling noise. How long has this system been setup?

If you're certain there's not some kind of blockage inside the plumbing, (a snail would be one suspicion) you'll need to adjust the flow of your return pump to match the flow in the drain.

 

[kara13]

Tank has been up 10+ years. The air part of the overflow was blocked. I could use a wire to unplug it quite a bit, but the pipe seems to be plugged up about 12" down from top now. It's working, but loud. Guess i'll be taking the pipe apart from below and running a pipe cleaner up

Thanks. I didn't totally understand how that part of the tank worked.

How clean do you keep your overflow area? I think I had too many worms in there and they are probably clogging it.

 

[Reefing102]

I don’t clean my overflow area but it’s only been up for a couple years. I agree with @Timfish theres likely still a block in there.

What size tank is it?
Do you know the size of the plumbing?

@BeanAnimal any additional thoughts?

 

[kara13]

Tank is 100 gallons. Pipe is 1.5" or so.

I have it working now. But can still feel a block about 12" down the pipe. I think I'll tackle taking the pipe off from underneath tomorrow.

Thanks for the help!

 

[Reefing102]

Just for a reference a 1.5 drain seems to drain at a conservative rate of 1,400 GPH to 2,100 GPH. It depends on which chart you look at. So depending on your pump head, it may be too strong or weak. With a blockage, the flow is obviously restricted which will mess with the balance (if I’m understanding everything correctly).

 

[Reefing102]

Forgot to post the reference charts

 

[kara13]

That's great info to have. Thanks!!!