need some help with corner overflow

[pikachux3]

I want to diy a corner overflow in my 240 glass tank, but I have a few questions/concerns. I will be drilling the bottom of the tank. As for the return pump, I would like it coming out from the overflow box. I want the tank to have an extremely clean look. This was all because I went to a fish store and saw this clean looking tank. The tank had a corner overflow AND had some sort of return pipe coming out of the wall of the overflow.

In my mind, there are going to be two holes at the bottom of the corner overflow. One hole drains into the sump, and the other hole pumps water out of the wall of the corner overflow.

My concerns/questions:

1. Is it okay for the return pipe to be so close to the corner overflow?
2. Does this type of corner overflow make noise? If so, is there a way to reduce it?
3. During a power outtage, wouldn't a tank (with the set up described above) drain all the water using the return pipe?
4. How big should the drilled hole be that is going into the sump if my sump pump is rated 1200 gph?

Thanks for your time. =)

 

[jlnguyen74]

My concerns/questions:

1. Is it okay for the return pipe to be so close to the corner overflow?
2. Does this type of corner overflow make noise? If so, is there a way to reduce it?
3. During a power outtage, wouldn't a tank (with the set up described above) drain all the water using the return pipe?
4. How big should the drilled hole be that is going into the sump if my sump pump is rated 1200 gph?

Thanks for your time. =)

1. It's ok for the return pipe to be so close to the overflow
2. Overflow box makes noise. You can either fill it with bioball, or make a durso stand pipe to reduce the noise
3. If you do it right, your tank won't drain all the water. If you do it wrong, you'll flood your house
4. For 1200gph, you need a 1-in bulkhead, the drilled hole is slightly bigger, I think it's 1-1/4".
BTW, make sure to add a check valve on your return line, so the water stop draining at the grid of your overflow box, instead of draining all the way to the return outlet.

 

[pikachux3]

Thanks for the detailed answer! Is the last thing you said the solution to question #3?

 

[jlnguyen74]

Thanks for the detailed answer! Is the last thing you said the solution to question #3?

No, the last thing I said pertains to the attached picture, where the return outlet is below the cut slots. In regards of question #3, I've seen a few tanks with DIY overflow box, and recently has a personal experience with one, when the DIY overflow box was not glued/attached correct, and water drains/leaks into it from all over the overflow box, instead of just from the cut slots. When the pump is off, water keeps coming to the overflow box, even when it's below the cut slot. If you fill the overflow box with bio-ball, your tank will be drained until water reach the point that it can't come into the overflow box. If you put a durso stand pipe with the opening flush with the cut slot, then it will solve the problem.