Correct height for Mega Flow Standpipe

[ken6217]

Are the three holes near the top of the standpipe supposed to be above, in the middle, or below the top of the water line?

Also is it better to have the flow from that standpipe discharging below the waterline or at the waterline in the sump? I was curious about this because when I turn my main pump back on after feeding, the waterlevel in the tank fills very high due to the fact that the water does not seem to return to the sump right away. I was wondering if maybe there was back pressure or something since the pipe was submerged.

Thanks,
Ken

 

[mladencovic]

Assuming you are talking about the MegaFlow overflow kit from AllGlass (durso pipe), the only important thing is to make the small hole on the top of the pipe above the water (controls the intake of air in the pipe) and the bent down intake and all other holes, fully submerged in the water.

Because the flow rate through the overflow drain pipe is only and completely determined by the gravity, height of fall and the diameter (and to smaller degree certain things that can slow the flow like elbows etc.), there is a possibility that the return pump is too strong for that particular overflow. If the water is not spilling or getting dangerously close to spilling from the tank you are fine with the. Otherwise the return pump flow is too strong and you can do one of three things:
- Replace your pump with the weaker one
- Constrain the pumps return pipe by adding some kind of a valve to it or by some other means.
- Add additional overlow pipes and/or overflows. For example the overflow box on my AllGlass tank has one hole for that is intended for a return pump, but I use it for additional drain from overflow box and have return pipes running on the back and the side of my tank.

The lower you discharge the water from the pipe, the greater the flow will be and whether you discharge it below or above the water line does not have too much of an effect on the flow. However, discharging it above the water level in the sum will have the following undesirable effects - higher noise, higher splashing and therefore salt creepage and more microbubbles in the water. It might also make the surface of your sump very "wavey" which would be beundesirable if you are using toppof switches.

 

[ken6217]

Thanks for the help. Yes, it is a AGA Mega flow.

The pump does put out more than what the drain can handle. I have a ball valve on the discharge side of the pump because of this. The in and out is balanced. The only time that it doesn't seem to be is when I first tun the pump on. There seems to be a lag between the water coming into the tank and the water exiting it through the standpipe. This is for about 20-30 seconds.
Ken

 

[chase33]

I have a ball valve on the discharge side of the pump because of this.

This may not be a good idea as it shortens the life of some pumps. A better way or reducing the flow back into the tank is to divert some of the flow back into the sump. You can connect a tee to the return line. Connect a hose/pipe to one end of the tee to return water back into the tank, and another hose/pipe to run back into the sump. You can add the ball valve to the hose/pipe running into the sump to control the flow back into the sump.