Overflow box to return pump gph ratio?

[daveydoodle]

It's amazing to me that if you do not have a working knowledge of the plumbing mechanics of a larger aquarium, how confusing it can be!! I've spent the last month or so reading as many forums as I can trying to get this straight before I buy the necessary equipment, but I'm just not there yet. My question is still this;
180 gallon tank, 20 gallon long sump, Aro and a 1/2 dozen small (4"-6") SA cichlids, okay question(s)-
1) Do the overflow box gph and return pump gph have to be the same?
I'm looking at an CPR or Eshopps Overflow of about 1200 gph. Does the return pump have to be the same or a little more?
2) For a 180 gallon, should I be using a 55 gallon sump?
Some postings talk about not being able to get the flow rater right. Is more gph better because of the greater turnover of the tank? Should i be reaching for a minimum turnover per hour? Is 1200 gph sufficient?

PLEASE!! This thread will have 75 reads by tonight, but only 1 reply. Please let me know what works or didn't for you. I hate to order the equipment only to find out it's not going to work! For the people that have a 150 gal-200 gal, what are you using? If there are other variables needed to answer this question (ex: head height) please let me know.

 

[jcardona1]

the pump should not exceed the gph rating on the overflow box. other than that, you should be ok. it will work fine. basically, that gph rating on the overflow box is the number of gallons per hour that it can safely drain w/o overflowing and spilling onto the floor

 

[TRENT]

Yes 1200 gph will be ok. Remember each J-tube will return 600 gallons (so you will need 2). Also yes the 55 will work as a sump. Here are a few pictures of a sump I did out of a 55 and the overflow box setup.

 

[buddha1200]

i always match my overflow gph to the pump gph i use ball valve on the pump return line and just cut the flow back if it over powers the flow of the overflows(never had to cut back to much)

 

[Pharaoh]

http://www.monsterfishkeepers.com/forums/showthread.php?t=47105

 

[daveydoodle]

Pharoah-I read that sticky several times but that primarily addresses just the pump (no mention of the overflow box) and charts the gph @ different head heights. I understand you'll loose gph with the increase of head height. My question was realeted to the overflox box or return pump overworking in relation to the other.

Trent-your set up is phenomenal!

I found at my LFS (2) Eshopps 600 gph overflow boxes and bought them both ($15 each). Is there any problem with running two 600 gph boxes as opposed to just one 1200 gph? That way if one siphon ever breaks, the sump would still be operational, right? I'm looking now at a 950 gph @ 0 head pump; would this be strong enough? I plan on only running 4-6 feet max head height.

And I'm definetly going with the DIY 55 gallon sump tank.

 

[Pharaoh]

For the most part, overflow will flow right about what they say they will. As far as one 1200gph or two 600gph, either one will work.

With pumps, as long as the gph rating at the specific head height does not exceed the rating of your overflow(s), you will be fine.

I was planning on typing more, but had to jump off for a while. My aplogies for being short.

 

[daveydoodle]

So then knowing that my max head height will be about 4-6 feet max, I should be looking for a pump that outputs about 1000 gph @ that height? (to work with two overflows @ 600 gph each).
Sound logical?

 

[General]

basically think of it this way, the water coming out of your tank must drain at a higher gph flow than your pump returning the water otherwise the sump will be dry and/or overflow your main tank and possibly burn out your pump. so just over do the drainage and you will be fine. there are simple formulas to figure out flow rates all over the web.

 

[General]

so to answer your question the return pump must have less gph flow rate than the overflow box to you sump. also make sure that your sump doesnt overflow if there is a power outage or for me i like to turn the pumps off when i feed the fish so food isnt wasted.