How to figure out your bulkhead?
 

How would I go about figuring what size bulkhead I need for a new system? Anyone have a link or anything for calculating which size I need?

http://www.reefcentral.com/calc/drain.php

Show's what size pipe to use for your overflow. If you want to be super safe, then use 2 bulkheads for redundancy, or at least go a bit bigger than the minimum size recommended.

You are my hero! I spent an hour trying to google this with no luck! :mrgreen:

So...
Using the following input parameters

Gallons per Hour = 2500
Drain and Overflow sizes are calculated as

Recommended minimum drain pipe diameter = 2.06 inches
Recommended minimum linear overflow size = 38 inches

So....what does linear overflow size mean?

I think it means that if you had a square and all 4 sides were 2" long, the linear length would be 2"x4 sides = 8"

yeah, linear overflow would be the sum of all the sides of your overflow box (the part with the teeth in it). This can be cheated a bit but you will have a faster and noisier flow into your overflow box.

Oh....I think I may have found a flaw in my design...

I want to do an external overflow box, and I didn't really want to to make it a full 1ft tall only like a half sized box. Originally I planned to run two drains in the overflow. Am I going to run into difficulties?

If you're doing two drains you should be fine as it says you need 2.06 inches of drain. I would imagine you're going to do 2 x 1.5" (standard)? By increasing the drain size I would imagine it decreases the amount of linear overflow you need.

Its not the depth of the box that counts but the length that the water actually overflows over. By increasing the gaps between the teeth you can also get away with more flow.

Okay, I think I understand this now. First up thought I think I need to firm up some of my overflow plans, then maybe I'll post them here via google sketch up for some review.

Thank you!