Tyring to understand

[barebucta]

Guys I'm a little confused can see if you can help me with some calculations; as a rule of thumb, generally for every 1" hole you're expected to get 600gph flow correct? Using the same logic, is it fair to say then if you have a 2" hole you'll get 1200gph? Also why is it that with the 1" holes the return hole is 3/4"? If there was a 2" hole would the return be 1.5"? Deanos any links???

 

[reefman]

i dont think doubling the size hole doubles the flow rate.
i found 1" drain will drain 1000 gph but we all use some type of standpipe to restrict the flow.

 

[ming]

2" hole will be more then 1200gph. Theres more then double the surface area to go through with a 2" hole so it goes faster then 1200gph.
Think Pi R squared for surface area
1" = .785 square inch
2" hole = 3.14 square inch
The 2" hole is about 4 times the surface area so I'm pretty sure its 2400gph

return is usually 3/4" because the return pump can pump faster because theres a lot more pressure being blown into the tank. The drain hole is gravity fed so theres not much pressure so its going slower

 

[TimberTDI]

A 2" bulkhead can drain just under 2500gph.

 

[Hotwheels]

I believe these are maximum that can be achieved for flow, but when calculating the return you need to consider the source (return pump) not just the path way. This will in turn dictate the flow to the sump.

hope I didn't confuse you more.
long story short, both ends need to be balance.

http://www.reefcentral.com/calc/drain.php
http://www.savko.com/ViewTopic.asp?messageid=3

 

[Tonyscoots84]

i have a 1.5 inch drain and it approx. drains 1200gph..