Sump.

[cccapt]

Originally Posted by copi

I am not trying to be argumentitive, only to understand...

There is nothing better than asking questions if you don't fully understand something.

I tend to agree with you on the U-tube overflow as being more reliable than the CPR style which also relies on a lift pump to work properly. I used a U-tube over flow for close to 20 years and it never failed once. Not saying it can't fail, but IMO they are very reliable.
The siphon in the U would only be broken if air accumulated there...and that would probably be caused by using a pump thats too weak. What makes a predrilled overflow so much better is there isn't actually a siphon that needs to be kept. Water is pushed down the overflow pipe.

Ziggy, your overflow is definitely different than mine. You say water can enter the overflow from the slots near the middle and bottom? That's pretty scarey. You can't change a bulkhead without draining your tank? If by some chance a bulkhead started to leak, it can drain your entire tank?
My overflow has those slots, but it's only a cover than can be removed. The theory behind that is water will be drawn up behind the cover and into the overflow. Dunno if it actually does that, but I can take out my bulkheads and nothing will drain out of the tank...only the water inside the overflow itself would need to be drained.

[Ziggy953]

My tank is not drilled I use an overflow box. There are no bulkheads in my tank. I was talking about the slits in a standard AGA tank...and they work exactly like you described. The point is to pull water from more then one zone in the tank.

[fijiwigi]

since we are on the topic. I have an overflow box that flows into my sump.
The overflow box makes a lot of noise when the water flows into the pipe connected to the drain of the overflow box. The water flowing into the sump is silent. I am wondering if there is a way to quite the water flowing into the box. It is noisy. Is there a way to connect the u-tube directly to the down pipe so there is no air at all??

[cccapt]

OK...got ya. I thought you meant those slots go right thru to the other side of the overflow. I really don't think they draw up much water, if any. It needs some kind of "pull" to draw the water up, but it looks like a good concept...lol. Regardless, the predrilled tank are undoubtly the way to go.

[cccapt]

Originally Posted by fijiwigi

since we are on the topic. I have an overflow box that flows into my sump.
The overflow box makes a lot of noise when the water flows into the pipe connected to the drain of the overflow box. The water flowing into the sump is silent. I am wondering if there is a way to quite the water flowing into the box. It is noisy. Is there a way to connect the u-tube directly to the down pipe so there is no air at all??

A picture speaks 1000 words.

[austinsdad]

Overflow (drilled) with the Durso standpipe gets my vote.

[Ziggy953]

If you put an 90 elbow on your drain in the overflow box it will quieten it down some. The only way for it to be silent is to do like they do with the durso standpipe and have the drain draw water from below the surface.

[fijiwigi]

The above photo looks like ccapt just added a plastic cup in the overflow box with a hole cut out for some tubing. I would assume the tubing is for air to help feed gravity and the tubing draws air quietly. And I would assume the cup helps to muffle some noise. How do you keep from the cup moving around too much and tipping over?/

I would also assume that a 90degree elbow would minimize the swirling flushing sound because there would be less gravity.

I still don't understand what a Durso standpipe is.

[roka64]

CCC did a DIY durso standpipe and it looks like he put some foam on the left side to keep it from moving. At least that is my take.

[cccapt]

Yup, just a plastic cup with an airline. That's a piece of eggcrate on the left side to keep the cup in place. The cup is sort of wedged between the front, back and one side. It is dead silent and costs virtually nothing.

If you use a pvc 90, actually 2 of them to make a U shape, you will need to drill a hole in the top to let air in too....but it may not fit inside the overflow box.