Looking for advice on corner overflow box, and sump flow.

[Duglis]

I am about to start drilling my 29 gal tank for a Herbie overflow setup. I plan on drilling the back of my tank and would really like to keep as low of a profile as possible. I guess my first question is how to make an overflow box doesn't take up a lot of space? I've seen photos and descriptions of rounded ones that looked nice, but since I plan on drilling the back of my tank (my stand has a hard-top) I'm not sure if that would work.

I am using two 1" overflows (90 degree turns, one up, one down) and a 3/4" return to and from a 10 gal sump. I intend to use a gate valve on my siphon and a ball/check valve on my return. Is this possible if my return is tube instead of PVC?
Also, any suggestions on how powerful a return pump I should use?

Any and all advice is welcome, I have big plans for this setup, and I would like to stop wasting money doing things wrong.

 

[thegrun]

Most overflow boxes are made of acrylic, it's easy to work with once you practice a little, acts very much like hardwood, use either a blade made for cutting plastic or a fine toothed blade. I would use a gate valve as well on your return rather than a ball valve, you will find it much easier to adjust. You will want a pump that delivers at least 150 GPH after head pressure loss. Assuming a 4' head pressure, an Eheim 1250 would be a great pump to use. I would not use a check valve, they will fail sooner or later. Drill a small hole near the top of your return to act as a siphon break and be sure your sump is large enough to handle all the drain down water when your pump is off or you will have a flood. You could use several barbed fittings if you have your heart set on using tubing, but it would be easier and less expensive to use PVC and just a small piece of tubing at the bottom of the drain line and as an attachment to your return pump.

 

[Duglis]

Most overflow boxes are made of acrylic, it's easy to work with once you practice a little, acts very much like hardwood, use either a blade made for cutting plastic or a fine toothed blade. I would use a gate valve as well on your return rather than a ball valve, you will find it much easier to adjust. You will want a pump that delivers at least 150 GPH after head pressure loss. Assuming a 4' head pressure, an Eheim 1250 would be a great pump to use. I would not use a check valve, they will fail sooner or later. Drill a small hole near the top of your return to act as a siphon break and be sure your sump is large enough to handle all the drain down water when your pump is off or you will have a flood. You could use several barbed fittings if you have your heart set on using tubing, but it would be easier and less expensive to use PVC and just a small piece of tubing at the bottom of the drain line and as an attachment to your return pump.

Awesome, just the kind of advice I was looking for. Thanks a ton.

 

[CStrickland]

I made mine with black acrylic, I'm really happy with it.
The broader it is, the better it will skim the surface, giving you better oxygen exchange and taking the dirtiest water. So you want to balance that against something tall with a narrow top. I think the slimmest style is a "ghost overflow" maybe you could find a diy vid on YouTube or something. Keep in mind that barb fittings are going to restrict flow a lot more than pvc slip fittings because they go inside the tube, narrowing it. You'll want to factor that into your calculations.

 

[Duglis]

I was thinking something simple, like a 10" span across one corner. I would love to bend the acrylic into a bow shape in the corner for more surface area, but need advice on how to get the curve.

 

[Duglis]

Furthermore, if my pipes are both at the top of the tank, do I need a long overflow box?