Overflow issue

There's no kink in the tubing. The outside box level is about 1 inch under the inside water level when it's running.

 

It's a rough sketch but,

like this?


TJ

 

I can't see that clearly enough, except to make out that the proportions are pretty off. I'm going to take a pic or two of the actual setup in a minute, but here's a diagram for now:

 

I enlarged the pic, sorry. I exagerrated the proportions just for demonstration purpose. Pics of the set up would be helpful ;D

TJ

 

Raven, on the inner box did you cut any teeth at the top where the water flows into the box? and if so how far did you space them?

just throwing out thoughts as it seems you are having a restriction of flow somewhere.

also just for a test try adding another utube side by side and see if that increases the flow, if it does then you need a bigger utube if not then the problem lies elsewhere.

 

The teeth are (not evenly spaced, used a dremel to cut them with the router attachment) about 1/8th of an inch apart, and I cut them using the 1/8th inch bit.

In these pics, the 3/4 vinyl tube is the one with a siphon. The other one is the original tube, 5/8" with 2 right elbows. It's still there because I need to build onto that black piece, or there's nowhere for this overflow to hold on (like the side of the tank).

Here's some pics:

 

When you pan is filled to the top and you start the syphon does the flow seem greater until the water gets level with the inner box? another words does the flow slow down when the water starts to go through the teeth?

also I wanted to point out that flex tubing like that isn't going to be a constant 3/4, I bet if you through a rigid utube on there it would flow allot better.

 

Try taking the sponge out from under the overflow so it's a little lower and make sure the exit of the U-tube is lower than the intake side. Other than that you should have a pretty good flow but I wouldn't expect more than a couple hundred ghp.

After scoping around it looks like most if not all comercially available overflows use 1 1/4" to 1 1/2" acrylic tubing for the U-tube. A lot bigger ID than a 5/8 or 3/4 hose. It should work but will it be enough?

TJ

 

You mean, does the water inside the pot rise until it's flowing over the teeth instead of through them?

The thing about the other overflows is that, if you look at the eshoppes overflows, they have 1 1/4" tubing on their 300 gph overflow, all the way up to a 800gph overflow. If 1 1/4" works for 800 gph, the 3/4" should work for >400GPH because 3/4" tubing has over half the surface area in a slice that 1.25" tubing does.

 

I mean are you getting more flow on the output when the water is over the teeth. and when the water gets to the level of the teeth does you output slow down.

also here is a good thread made a while back with someone that had the same issue:
http://www.3reef.com/forums/i-made/new-sump-overflow-box-problem-75340.html

I figured it might give you some ideas.