So in the back part of the overflow, even with the standpipe, is the water level lower than the divider?
Increasing flow of a hang-on overflow box?
- Thread starter j_chicago
- Start date
The drain is throttled back to cut down on the waterfall noise but its still lower then the divider, not by much, maybe .5" or so.
Are you sure your water level is high enough? It may not be. Add water to the tank until it fills the sump approx 1/2 way. You may have to low of a water level.
A 1" tube can handle approx 700gph at max. 600gph is usually the average.
A 1" tube can handle approx 700gph at max. 600gph is usually the average.
I'll try more water, but when I open the valve up more, the pump compartment in the sump drains quickly, and the tank gets dangerously close to the top.
a single 1" bulkhead will flow up to about 600gph, when its draining free...I think maybe a 1" U-tube might be lower since the water height difference is so small from back to front...?
Sorry, was at work this afternoon and checking the post on my blackberry, missed this post.
The bulkhead is 1.5", but I reduced it to a 1" because I did not feel like buying another 8' piece of PVC, seeing I already had large sections of 1" laying around.
So I have two 1" U-tubes, and a 1" drainpipe that I cut flow to reduce the noise, but even wide open it does not allow more flow.
Thanks again for all the replies, guess you guys remember how frustrating it can be.
OK,
so reading online and someone somewhere on some 3 year old post said:
Reducing the length of the U-tube going into the back portion of the overflow will reduce the resistance the water has to be pushed down to, there fore increasing the flow.
Currently I have 5" more of U-tube pipe below the top of the barrier wall. But I also don't want to reduce the ability to restart the siphon itself if the pump stops and restarts.
Thoughts?
so reading online and someone somewhere on some 3 year old post said:
Reducing the length of the U-tube going into the back portion of the overflow will reduce the resistance the water has to be pushed down to, there fore increasing the flow.
Currently I have 5" more of U-tube pipe below the top of the barrier wall. But I also don't want to reduce the ability to restart the siphon itself if the pump stops and restarts.
Thoughts?
The only thing that controls the speed of the siphon is the difference in height between the source container and the destination. Say you have two containers (i.e. the front part of an overflow box (the tank), and the back part of the overflow box). Now, say that when its running, the tank water level is 3/4" higher than the water level in the back of the box. Even if the back of the box was 10 feet deep, it wouldn't matter if the hose is two inches from the bottom or two inches from the top. The height differential (and therefore the pressure differential) is the only thing that influences a change in flow rate. Hopefully I explanined that clearly enough.
The only other thing I could say would be to lower the overflow box on the rim of the tank as much as possible - most boxes have little plastic screws to adjust the height of the box, and therefore the water level in the tank. If you get the box as low as possible, this might allow a larger pressure differential from the front to the back to bump up your flow a little.
The only other thing I could say would be to lower the overflow box on the rim of the tank as much as possible - most boxes have little plastic screws to adjust the height of the box, and therefore the water level in the tank. If you get the box as low as possible, this might allow a larger pressure differential from the front to the back to bump up your flow a little.
