Looking for caculator for bulkhead size

[TheReefGeek]

No, the linear measurement means how long of a distance the water can flow over.

Imagine a waterfall. It is 10 meters across. This is the type of measurement you want.

Now for your overflow, say you have a standard corner overflow, you have two lengths you have to add up for the total linear measurement.

It's for drains. So that would probably mean "free flowing".

"Probably" is not a good term in plumging a reef. Leads to too many floods. That is why this calculator is dangerous. Good as a gernal guide though, a starting point better than nothing.

If you have 20 inches of water in your overflow pushing down on the drain, it is going to flow faster than if you have 5 inches of pressure.

Also you can get some suction/siphoning going, but that is not recommended.