Sumps / Overflows


New member
Hey Greg

I'm new to the hobby, so bear with me if this is old material regurgitated. I just read part 3 of your sump articles (by the way, I can't find pt. 1 and 2, but Ill keep looking) and a question has arisen from the depths of my brain.

The tank I'll be getting for my reef is a 65 gal with a built in overflow box. There's this funky contraption on top of the drainpipe, and all I want to know is what the heck its purpose is! Its all one piece of plastic, part of it is a tube that fits inside the drainpipe a few inches, and the other part is kinda like a half sphere, with a smaller tube coming out at the top. Yeah... horrible description, huh? Haha. Well I'm hoping you've seen these so you know what I'm talking about. It always floats on top of the water in the overflow box, and allows air in through the top... if I had to wager a guess, it'd be that it cuts down on noise in the event of fluctuation of the water level in the box.

Thanks, I really enjoy your writing.



Premium Member
First off, the links to the first two parts:

Part I
Part II

Thanks for the kind words. That's what keeps me motivated for the next article. ;)

It sounds like you are describing an AGA (All-Glass aquarium) overflow standpipe. It also sounds like you've got a pretty good handle on what it's doing. It works on the concept that the drainpipe is always submerged, thereby preventing air from entering and causing "flushing" or "splashing" sounds. When the water level drops, the "float" closes the drain until the water level rises high enough that there won't be a problem with noise.

It's rather clever, and works quite well.

If that's not what you are describing, well, then I have no idea what it's for. :p :eek: :p


New member
:thumbsup: You're the man, Greg. Checked the AGA site and thats exactly what it is. And hey, for once, I was kinda right on something! Cool. Yeah I found those links after a little more searching, and after reading, I'm going to go with a super fancy, customized, signature edition RUBBERMAID container. Reefer on a budget. No, no, I take that back, I'm an even lower level... reefer in college!

Peace, and thanks for your help.


PS You keep the good articles coming, I'll keep the compliments going!