question about the overflow size calculator

[johns]

Maybe this question was better off here in this forum:

Can anyone please explain to me how the linear overflow size calculator here on RC is designed to work? Does it assume teeth are cut into the linear length, and if so, what sort of spacings, etc

For instance, I put in 1200gph as the flow rate and it recommends a minimum linear overflow size of 18". But I dont know how to relate this the overall overflow length because the overflow on my tank will come with teeth that are 5/8 inch apart on center and with 1/4 inch void spaces in between.

[RichConley]

so you have 1/4" gaps, with basically 1 gap per inch?

So basically, if you have a 12" long overflow, you've got slightly more than 4 linear inches of overflow.



Teeth are overrated.

[johns]

I think I see what you are saying, but the teeth are 5/8 inch on center, meaning the 1/4 gap is in between. So I basically have one 1/4 inch gap for every 5/8 of an inch.

But I'm not sure it makes logical sense. Lets say you have an 18" overflow. By this calculation, this would amount to approx 7" of linear space (18 divided by 5/8 = the number of spaces X 0.25 = the total space).

Using the calculator is sugests a 7" overflow can handle only 450gph. That seems awfully low.

I must be missing something. Maybe it just means that as you go above 450, you start to travel up the vertical height of the teeth?

[johns]

bump