Glassholes overflow setup?

[ChrisQ0904]

I bought a used tank to do one of my "dream" builds and I believe it comes with a glassholes overflow and I can't seem to figure out the drains because they seem level and would imagine they both would drain the same amount of water and therefore would be really loud.

Am I overlooking something or am I just a special case?! I attached pics to hopefully help out.

 

[redfishbluefish]

That appears to be a 1500 gph Glass-Holes overflow that comes with two 1 1/2 drain lines....that's normal. And yes, both drain at the same time. The only thing that looks different is that the one elbow appears to have two breather tubes coming out of it....I've never seen that before.

 

[ChrisQ0904]

That appears to be a 1500 gph Glass-Holes overflow that comes with two 1 1/2 drain lines....that's normal. And yes, both drain at the same time. The only thing that looks different is that the one elbow appears to have two breather tubes coming out of it....I've never seen that before.

The person I purchased from gave me 2 new elbows that have 1 breather that I will be replacing them with.

 

[fish farmer]

I have the smaller glassholes overflow. Recently I've started to push more water through mine and it has been louder.

 

[larryl]

I had the glass holes on a older 180. You have to have the tubes or it will gurgle like crazy.

 

[ChrisQ0904]

Thank you guys for the help, if I run into any issues once I'm set up I'll reach out again.

 

[redfishbluefish]

If it helps at all, you can check out how I set mine up HERE, with each of the drains entering the corners of the the sump, with the return section in the middle.