Custom external overflow dimensions

[ilaizm]

Hi,

I am building a new custom tank which will use a sump. I will be building a custom external overflow box too. I am interested in identifying the best dimensions for the overflow box. I know the ideal linear overflow size which would be the length of my overflow box. What I would like to identify is whether there is an ideal depth and height for the overflow box. My box will be similarly positioned to the one in the pic below. The two red arrows in the pic are the dimensions I am after.


84253


thanks

[kris2341]

IMO, the depth of the box (short arrow) can be any value you want as long as it is not obtrusive, is big enough for you to comfortably get your hand in there without any trouble and can accommodate your choice of bulkhead, So 4-6 inches in my case.

The length of the box (long arrow) matters even less as all good overflow designs utilize standpipes coming from the bulkheads some distance from the bottom of the overflow upwards. So this can be as long as the total total depth of your tank, or as short as 6-8 inches depending on flow rate just so you have all the options available depending on pump size if you go the same depth as your tank.

The overflow design you are showing is a perfect candidate for a herbie style overflow which would allow for optimal silence and flow rate.

http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/

If you are building a custom tank from the ground up, IMO I would just turn the entire wall you are considering into an overflow for the tank so it spans the entire length of the tank wall and is as deep as the tank itself so it looks less like an appendage sticking out of the tank and more like a one piece unit.

[MKD]

That's similar to my 300g tank, its 6" × 12" with 2× 1 1/2" bulkheads Herbie style. How big is your tank and size of drain pipes?

[ilaizm]

Thanks for the suggestions.

My tank is 150G. My drain pipes will be 1.5 or 2" wide. And yes, I am going to set up a Herbie Overflow.