Flow problem, need expert advise

[Homer Siped]

I think a 3/4 can only handle like 600 gph at full siphon? Your pump is rated at 1453 gph, not sure of your head height. I think if you bumped up to 1" after your overflow box, you might get better results?

 

[Lukemitchell]

What is at the top of the stand pipes above the tee?

Nothing just an end cap with a hole in it

 

[Lukemitchell]

I think a 3/4 can only handle like 600 gph at full siphon? Your pump is rated at 1453 gph, not sure of your head height. I think if you bumped up to 1" after your overflow box, you might get better results?

It's 1.3 meters and Ye I'm thinking to change to 1''

 

[Lukemitchell]

Isnt that basically a bean animal? I have only had experience with 1 setup like this but seem to me your pump is over powering the drains. 1 should run full siphon, other should take up the left over and 3rd is emergency drain which 90 should be turned up right. Least thats how i have mine from my understanding

View attachment 1247117

I had the box made for me I told him my tank details and he made that.

 

[millerkid519]

I ran overflow boxes for all the sumps at my last fish job and had similar problems. if there is even a tiny fluctuation in tube length or angle they will have different levels of flow. i fixed mine by putting ball valves in the drain lines and adjusting until they were more even. closing one off slightly forces more water to go through the others to keep the same flow rate. worked for me

From what I have seen (reading and watching videos) is that you may be looking got and consistency with your full siphon line not fully submerged. I could be completely wrong but thats where i wpuld start

 

[Homer Siped]

Have you tried slowing your pump down a bit? See if you can get things to balance out a bit?

 

[robham777]

Nothing just an end cap with a hole in it

So all three are the same. It seems to me the middle drain is running full siphon but the other two are draining by gravity. You may be able to tinker with the hole size in the cap to get them all draining off gravity, but I think your best bet is to add the ball or gate valves on the drains and go from there. What diameter feeds the overflow box?

 

[Homer Siped]

By looks id say its a bean animal that is incorrectly put together. The way there is 3 pipes with 90s turned down and a hole in 1 cap, all point to a bean animal set up.
http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

 

[Lukemitchell]

So all three are the same. It seems to me the middle drain is running full siphon but the other two are draining by gravity. You may be able to tinker with the hole size in the cap to get them all draining off gravity, but I think your best bet is to add the ball or gate valves on the drains and go from there. What diameter feeds the overflow box?

I think il add ball valves and if that doesn't work I will replace with 1'' drains and just leave 1 3/4 drain as a back up as I'm guessing 2 x 1'' drains will be plenty ?

 

[DN328]

I noticed you have an air tube on at least on pipe, but not on the other. Again from the pictures, it doesnt show that the drains are not keeping up given the water level in the overflow.

I think adding ball valves isnt going to address the issue if the main drain isnt able to take all the water alone.