Overflow and Pump?

[puffy_fish]

I am trying to figure out how much output/input I want from my overflow and pump. In a perfect world you would want this to match exactly. Can someone give me a good idea of how this works. I plan on using a sump with baffles but I need a better understanding of how i get the output and input to equal.
Thanks!!!

 

[kynekke]

Gravity makes them equal.. you don't have to do anything.. any amount of water your pump puts into the DT, the overflow will take the rest out and put it into the sump.. regulating the flow to match. I didn't believe this btw but I tried it anyway and it worked.

 

[groupergenius]

As long as the return pump has LESS gph than the overflow. It doesn't have to be exact.

 

[puffy_fish]

So for my 150 gallon tank...if I have a 900 gph pump (pumping up about 4 feet) and a 900 gph overflow...I would be fine..correct?

 

[groupergenius]

Originally Posted by PUFFY_FISH
So for my 150 gallon tank...if I have a 900 gph pump (pumping up about 4 feet) and a 900 gph overflow...I would be fine..correct?
Is this a predrilled tank? Or are you talking about hang on back overflows?
Either way, 900gph seems low for return in my opinion. But everybody does things different.
If you have 900gph return, you want at least a 900 gph overflow. In other words, your overflow could be rated at 5000gph. But if your only pumping 900gph into it. 900gph is all that will overflow.

 

[puffy_fish]

It will be an overflow tank. How large of a pump do you think I need?

 

[groupergenius]

It all depends on what you want to do. I have never run a refugium, but I think it's a low flow setup.
I am no expert by any means, but my setup on my 90 at home I think is a 1500gph return.
My tank at the office is a 120 with 3600gph return.
Like I said, it's all about what YOU want to do and what kind of sump you will be utilizing.

 

[scotts]

You can also buy a pump that is rated for more than your overflow and then reduce the flow out of your pump with a ball valve. Many people here do that. And the answer to your question is No it will not harm your pump to do this.

 

[puffy_fish]

Grouper's set-up seems like way too much gph compared to what i have been reading...any input?