Flow rate

[icepenguin1973]

What should be the flow rate to and through a refugium and a return pump size?In other words what size overflow box and return pump.

[OrionGirl]

For the fuge, I wouldn't go above 10--you want the water to sort of slowly flow through. The size of the overflow isn't as relevant as the size of the return--but even then, we can't really give you a size without knowing the head.

[icepenguin1973]

You wouldn't go above 10?Sorry I'm lost a little and what do you mean by head.I was planning on a 10 or 20 gallon fuge.

[OrionGirl]

10 gallons per hour turnover. Size is whatever you want--I had a 15 gallon sump on a 10 gallon tank.

[mogurnda]

I think she meant to not go over a turnover rate of 10X per hour. Head pressure is the result of having to pump against gravity. For each foot of height, a pump will lose a certain amount of flow, depending on the design of the pump.

[icepenguin1973]

So what you mean is, since I have a 75 gallon you wouldn't turn it over more750 gallons a hour.If this is correct then I could get lets say 600 gph overflow.then match up a pump after I figure on how high my piping is.Am I bothering you yet? :D

[mogurnda]

1. So what you mean is, since I have a 75 gallon you wouldn't turn it over more750 gallons a hour.
2. If this is correct then I could get lets say 600 gph overflow.then match up a pump after I figure on how high my piping is.
3. Am I bothering you yet? :D
1. For a 20 gallon fuge, you wouldn't want more than 200 gph
2. A 600 gph overflow would be great, but you can obviously make do with less.
3. Not yet. Keep asking :D

If you hunt around through this list (http://www.reefs.org/library/pumps/), you can get an idea of how much loss different pumps have with head pressure.

[OrionGirl]

No. What I'm saying is that you don't want the water going through the refugium more than about 10 times per hour--meaning, if we could identify each specific gallon of water in the refugium, every hour you would have 10 completely new gallons 10 times. the volume of the main tank is irrelevant for this, but you want much more movement than that in the main tank--closer to 15-20 gallons per hour turnover(this means powerheads and the water coming back from the fuge or any other external bits).

The overflow won't be running at it's maximum capacity, so the rating for it is not very relevant. You'll want a pump that moves 100 gallons an hour at the specified head.

[icepenguin1973]

So a 200 gph overflow or less would do fine but do they make'm that small.I know cpr has a 300gph.Hmmm,do you smell something burning.This is why I try not think,it stinks up whole house.

[OrionGirl]

The overflow speed is controlled by the speed of the return--it won't pull out more water than is going back in. They have a maximum capacity, but not really a minimum. At lower flow levels, the overflow won't be skimming the surface much, but it will still be moving just fine.

[icepenguin1973]

Ok I have the jist of what your saying.So any size overflow will work.2 things I was wondering.The water level has to be a certain highth so it slowly goes in overflow,but how do you set that point or is it trial and error.My second thought is can I have a small pump run outta my wet dry area into refuge,so in essence water goes into wet dry 2 pumps out.1 back to tank and one to refuge or that a disisater waiting to happen.It sounds like i'm babling,but I understand what you mean now,just fine tuning right my brain right now.

[OrionGirl]

Yes, you could have the water come from the wet dry into the fuge, and from the fuge into either the return area for the wet dry, or directly into the tank. I would want the line to split so some went into the fuge and the rest intot he wet dry, rather than having it hit the wet/dry and then go to the fuge--but that's just me. I wouldn't run a wet dry with media.

[icepenguin1973]

Where would you split it?

[OrionGirl]

Just before it spills into the wet-dry. You'd have to control the flow with the plumbing size or a valve.

[icepenguin1973]

So from the overflow just before it hits wetdry(just above) put in valve.What kind of valve.With this valve it is consistent flow?