Overflow box/ Return pump question

That's what you aren't getting.....the overflow GPH is the max flow it can handle....you can put less than that through it but not more (if you tried to put more than that your tank would overflow.

Saying you had an overflow that could handle 10,000 GPH but your pump only put out 1,000 GPH thats fine it'd still work but would be only running at 1,000 GPH that the pump is putting out....if your pump isn't putting the water back into the DT then it can't flow out...i.e what comes in must come out but no more than that. In this scenario you could ramp up the pump 9,000 more GPH to get more flow but the minute you exceed the 10,000GPH capacity of the overflow you'll start to overflow the tank.

Hope this helps.

 

+1 on this response. This explains it very well.

I have a pf800 on a 30 gallon cube with a 10 gallon sump - i wish it was bigger as i have a mag9 return pump which has to be valved back quite a bit.

Its always better to go a little bigger IMO - this will give you better surface skimming and better overall filtration.

 

Is this for a fuge only? Or a sump too? A fuge needs very little flow.

 

[QUOTE=SkyFire;1055904he overflow GPH is the max flow it can handle....you can put less than that through it but not more (if you tried to put more than that your tank would overflow.

you can put less than the top ratted amount, but if you go too slow it will get bubbles in the U-tube and fail eventually, so you want just the right amount.
As for flow to the sump and fuge a lot of people are splitting the flow to the sump/fuge and adding a flow restriction to the fuge side so they can run as much to the sump and still control the flow to the fuge.

 

Exactly what I do--I control the fuge flow with a ball valve, the rest goes to the sump. I just ordered a smaller pump as I realized I was running way too much water through my sump when powerheads can do the same. If anyone wants an almost brand new Eheim 1250 let me know!

 

Thanks skyfire, now I understand. For some reason I thought that if the overflow box has a 800 GPH, then that is how much it would send down to my refugium. I didn't understand that that is the max it can send. I feel a little bit stupid. Thanks for all of your help guys.

I am doing a regular refugium for those who asked. The water will come into one side where my protien skimmer is, then it will go over, under, over my baffles into the refuge, then over, under my baffles to the return area. I just want to make it simple.

 

Then again, I may go with the refuge on one side, and T it off to the intake and protien skimmer and the return in the middle. Which is better?

 

Best to independently feed and control the flow to the skimmer/fuge sections.

You want a lot of flow through the skimmer compartment and barely a trickle through the fuge. If you force the full flow of your sump through the fuge it will not work properly IMO.

 

Return in middle is the way to go. If the fuge is in the middle you'd have to make the whole sump run very little water through it. Have the skimmer section dump most of the water in the middle with the fuge side dumping a small amount.

Better yet--read this:

http://www.3reef.com/forums/reef-aquarium-articles-how-tos/all-about-sumps-filters-fuges-79852.html

 

that's what I'm talking about! :thumb_up: this lets you run as much water to your skimmers (I might run a heater here too) as you want, and lets you slow the flow to your fuge.