Do I need a valve on sump plumbing?????

[Blom]

Well to state that the equation isn't useful here I believe is wrong. You are correct that it depends on a few things, such as air water mixtures, whether or not it is laminar/turbulent flow. You could easily solve for a Reynolds number and jump into a whole bunch of fluid mechanics equations. But the RC calculator would of course be the fastest and simplest way to go. Good find.

[sphelps]

Nah it's pretty much useless, it depends on more than a "few" things.

[Blom]

Hah ok... well that was a good chat.

Im sure the RC calc has accounted for all these variables then.

Have a good one.

[mark]

drain size from RC (gravity)

Beananimal's siphon calculator

[intarsiabox]

I think 1" drain on a 50g is adequate. Have a valve on the discharge side of your pump and use it to tune your flow. If you are getting lots of bubbles from the discharge pipe into your tank close the valve until they stop, likewise if the return section of your sump keeps fluctuating, as it should remain at a constant level (with evaporation as the exception of coarse). It's that easy!

[windcoast reefs]

Originally Posted by mark

drain size from RC (gravity)

Beananimal's siphon calculator

I used the calculator that you showed, and it seemed to back up the size of the pipe and the flow rate. So So far it seems like a 1" pipe will work for me with a valve on the return.