what should my overflow look like running

[jonathon0883]

i have a lifereef single 700 gph hob overflow.. the question i have is...should the box that goes into the main tank be full of water? or should it only have enough to cover the U tube? and should the box that hangs on the bank of the tank be full of water or just partial? thanks for the help!

 

[jagermeister]

I'll try to answer this based on my overflow.
The box that's in the main tank is not completely full of water. There's just enough in there to cover the u-tube which is what you want. Water flows over the "teeth" on the edge of the box and falls a couple of inches into the box. This helps aereate the water.
Now, here's where we may be different because I have an Amiracle overflow. On the back the first chamber is completely full as it spills over into the second chamber. The exit of the u-tube is submerged in this first chamber. There's only about a 1/2" drop from the first chamber to the second chamber because I installed a standpipe in the second chamber to raise the water surface and reduce the noise of the overflow.
HTH

 

[broomer5]

jonathon0883
If the inner box is full of water - then you either have too much return pump, a dirty prefilter, air bubbles in your U tube or a restriction in the drainline.
Any of these will cause the water level to rise too much and completely fill the inner box - which is not good.
As jagermeister mentioned - the inner box water level should be up over the end of the U tube, but not so high that the tank water does not "fall" through the slotted teeth.
You won't get much surface scum removal if the water can't fall into the box through the teeth - plus - it's right on the border of failing.
Maybe throttle back on the return pump with a ball valve in the return line - if this is your situation.

 

[escape2thewater]

Thanks broomer! You may have prevented a future problem for me that I didnt know I had. My overflow was just a hair lower then my my tank level - thought this was normal......as per your advice turned down the ball valve on my return and everything now 100% a- ok!
Kyle