Overflow and return pump.

[Zactheninja]

Okay so I have a large sump, looks like its probably for about a 200 gallon.(pic)
And it looks like I'm ethier going to have to get two over flow boxes or one larger one.
I like the CPR over flow boxes, but it would be cheaper to get the larger one than two smaller ones.
The smallest large one that's has two bulkheads has a flow rate of 1200 gph, is that way over kill for a 100 gallon tank?
I would need a 1200 gph pump aswell for my return?

 

[Andrew McFadden]

What's the size tank and how about stock?

If its a 6' tank or longer I'd go with two

 

[Zactheninja]

100 gallon long. And it's not set up yet.

 

[Andrew McFadden]

I would go with two then one on each end. Will see what others have to say other then just me. I like to have more than one opinion when I post or start threads so I'm sure you do too

 

[Zactheninja]

Okay, I like lots of opinions.
It would probably be about the same price ether way.
I just don't know to go with tons of flow or less.
If I go with the larger one it would be 1200 gph.
If I go with two small ones it would be 600gph.
I will probably be stocking with lots of fish and coral.

 

[manbeast]

the overflows only draw down as much water as the return pump can supply, so I have to ask do have the return pump yet if so what is the flow rate at max and what is the flow rate with your tanks head height factored in

 

[Smudgy35]

I'd go bigger more flow has got to be better considering most people recommend 30 times that of your tank 600 gph just won't cut it

 

[ccCapt]

The recommended flow rate thru a sump is 5-10x your tanks water volume. So for a 100g tank you are looking at anywhere from 500-1000gph. The 30x number is the amount of circulation in the tank and that's accomplished with powerheads.

 

[Zactheninja]

Here's the link to the boxes I was looking at.
http://www.marinedepot.com/ps_aquar...ow_boxes_cpr&gclid=CKmrnaTTrrICFUdvTAodBW0AyQ

 

[Zactheninja]

the overflows only draw down as much water as the return pump can supply, so I have to ask do have the return pump yet if so what is the flow rate at max and what is the flow rate with your tanks head height factored in

These boxes say their gph?...
Explain please.

 

[Ingy]

If your return is only pumping up 1000 gph, then that's the most that will overflow into the box. So your 1200 gph will be able to drain it back down as fast as the pump is returning it.

The critical thing is to make sure your overflow can handle the flow the return is pumping out. Otherwise your return section of the sump will allow air into the pump. Not good.
Of course, a restrictor valve in the return will help prevent that.

 

[manbeast]

the overflows are rated at a certain gph as well as the return pump is rated at a certain gph as long as the return pump doesn't pump the water back up faster than the overflow boxes can draw the water back down you shouldn't have any issues, example the overflows in the 150 I have have a combined flow rate of @1400 gph the return pump is rated at a flow rate of @1350 gph but factoring in the head height of 4 1/2feet the effect of gravity on the water in the return lines reduces the pumps flow to @ 1200 gph which the overflows are more than capable of handling, if my overflows were rated at 1000 gph and I still ran the pump at 1200 the tank would quickly flood, but on the other hand if I had overflows rated at 2000gph and ran the same pump at 1200gph the overflows would only draw the 1200gph provided by the pump as the overflow can only take the water down to a set level, I hope this better explains what I meant in my first post, just getting up for work and haven't had my coffee yet so the brains processing a little slowly, my apologies

 

[Zactheninja]

Okay so if I got the 1200 over flow box and a 1200 pump it wouldn't work?
(I'm running slow today too, thank you guys for being patient.)

 

[danbstrong]

Okay so if I got the 1200 over flow box and a 1200 pump it wouldn't work?
(I'm running slow today too, thank you guys for being patient.)

Just my opinion you dont need 1200gph goin thru your sump 600-1000 gph is what i reccommend that is if your skimmer is insump and fugi because they will work more efficiently if water is not flying past if no skimmer or fugi in sump then go big to increase flow

 

[Zactheninja]

I was actually considering a hob skimmer, but I'm not sure about it.
So you think I need to do the two over flows? That would hit about 600gph. And if I got a 600 gph that would work right?
I'm just going off of what it says for gph on the over flow,

 

[danbstrong]

I was actually considering a hob skimmer, but I'm not sure about it.
So you think I need to do the two over flows? That would hit about 600gph. And if I got a 600 gph that would work right?
I'm just going off of what it says for gph on the over flow,

Yes return pump should be equal or less than overflow rating is it hob overflow?

 

[Zactheninja]

Yeah, tank isn't drilled.

 

[danbstrong]

Yeah, tank isn't drilled.

My hob overfow came with i think it was 1" u-tube i ended up buying 2- 1.1/4" u-tubes to handle a 800gph return pump i believe each u-tube rates at 500gph each so just make sure overflow is rated higher than whichever pump you use but try and make it close or your u-tubes will get airpockets in them resulting in flood

 

[danbstrong]

I was actually considering a hob skimmer, but I'm not sure about it.
So you think I need to do the two over flows? That would hit about 600gph. And if I got a 600 gph that would work right?
I'm just going off of what it says for gph on the over flow,

Back ti this ? Yes if overflow is rated at 600 you got pump at 600 youd be fine remember to calculate the gph loss for however far the pump has to push the water

 

[Zactheninja]

My hob overfow came with i think it was 1" u-tube i ended up buying 2- 1.1/4" u-tubes to handle a 800gph return pump i believe each u-tube rates at 500gph each so just make sure overflow is rated higher than whichever pump you use but try and make it close or your u-tubes will get airpockets in them resulting in flood

Okay. I think I got this now, thank you!