Max flow through sump?

[GlassReef]

I think I did some faulty planning regarding sump size for my 375gal (600gal total) system. Searching didn't come up with anything that directly addressed my questions so:

Display tank - 375gals
Fuge - 75gals
Frag tank - 75gals

Display return - Dart
Fuge/Frag return - Dart

Planned sump - 75gals 48" X 24" X 16"

I'm starting to worry about the sump being able to handle the flow created by the two Darts - approx. 5000gals. I thought that with all the large system knowledge here on RC, someone might be willing to relate their experiences with a system similar to what I've described. Do you think a 75gal sump will handle the flow?

Thanks

 

[mm949]

it depends on backflow...a taller tank might be better

 

[GlassReef]

<a href=showthread.php?s=&postid=13570328#post13570328 target=_blank>Originally posted</a> by mm949
it depends on backflow...a taller tank might be better

All my overflows will be smooth (no teeth), so I'm assuming 1/2" of overflow per tank, plus the overflows themselves. That would be 8gals for the display, 6gals for the overflow box, and 4gals each for the fuge and frag tanks. Total = approx. 22 let's call it 25gals. So, I'm thinking if I ran the sump half full I should be OK for backflow. To be honest, I wasn't so much worried about backflow (although maybe I should be ) as I am about the amount of flow through the sump. It's the 5000gals going through that 75gal sump that makes me nervous. And my main question is - should I be?

 

[Elliott]

the volume and rate of flow through your sump is limited by your display's maximum overflow capacity, in other words the ability of your display to handle your sump's return before it overflows, is your maximum volume and flow rate. your display's overflow capacity depends on the size and teeth of the overflow and the size of the plumbing from the overflow box to the sump. the sump's return pump just needs to be large enough to handle the flow it receives and pump it back to the display

 

[Elliott]

Tom, since your tank's overflow boxes are already built one option you have is to size the plumbing from the overflow boxes to your sump such that the rate of flow is 2-5 times the volume of your display per hour. since your display is 375g I would keep your flow rate under around 2000gph (375 x 5 = 1875), much higher and you overcome the sump's capacity to process the water flowing through it.

 

[flyyyguy]

how much water you move through your overflow, and therefore through your sump should be directly related to how much water your skimmer can process.


If you move any more water than this by your skimmer, then you are intentionally sending unskimmed (or less than adequately skimmed dependign on yoru set up) water back to the tank which defeats the purpose of efficient surface skimming in the first place, as you are just recircing this "dirty" surface skimmed water back to the tank before it can be skimmed adequately.

You use a toothless overflow with the idea in mind of surface skiming as efficiently as possible. Why do soemthing that makes the effort you put into setting that up, effort spent in vain??

 

[GlassReef]

<a href=showthread.php?s=&postid=13572142#post13572142 target=_blank>Originally posted</a> by flyyyguy
how much water you move through your overflow, and therefore through your sump should be directly related to how much water your skimmer can process.

If you move any more water than this by your skimmer, then you are intentionally sending unskimmed (or less than adequately skimmed dependign on yoru set up) water back to the tank which defeats the purpose of efficient surface skimming in the first place, as you are just recircing this "dirty" surface skimmed water back to the tank before it can be skimmed adequately.

You use a toothless overflow with the idea in mind of surface skiming as efficiently as possible. Why do soemthing that makes the effort you put into setting that up, effort spent in vain??

You coulda told me this before I bought the Gold Dart!

Seriously - what you're saying make sense. Thanks for the input.

 

[flyyyguy]

the dart is still a sweet pump for this application and what I typically suggest using for return pump. I use a dart for both of my systems, even my 90 which I am only moving a few hundred gallons through my overflow. I will add that I power my chillers as well of the returns off of one pump. They are quiet and can be tapered back to whatever you need. Just put a ball valve on the output side and use what you want

 

[8BALL_99]

flyyyguy hit the nail on the head. No reason at all to move so much water through your sump. All you need is enough to feed your skimmer chiller/heaters ect. You probably don't even need 2000gph. I use a 1260 on my 190 and its more then enough to feed my sump. Get your flow for your tank from Powerheads or a closed loop not your return. Dart gold still isn't a bad choice for a return. Even more so if you use it to also feed other equipment. Dont think you need two though

 

[flyyyguy]

the chiller is actually seperate from the equation of how much goes through yoru overflow. I just have the chillers set up on a closed loop from the retrun pump right back into the return section.

It probably costs a little on the chillers efficiency doing it that way, but I am more concerned with my skimmers efficiency so would rather sacrifice it there and run the appropriate amount through the tanks overflow.

I also use toothless external coasts to coast overflows on my tanks as I do very much believe in setting up everything around the skimmer to get the most out of it

 

[GlassReef]

<a href=showthread.php?s=&postid=13572542#post13572542 target=_blank>Originally posted</a> by flyyyguy
the chiller is actually seperate from the equation of how much goes through yoru overflow. I just have the chillers set up on a closed loop from the retrun pump right back into the return section.

It probably costs a little on the chillers efficiency doing it that way, but I am more concerned with my skimmers efficiency so would rather sacrifice it there and run the appropriate amount through the tanks overflow.

I also use toothless external coasts to coast overflows on my tanks as I do very much believe in setting up everything around the skimmer to get the most out of it

Thanks for mentioning that - I was just going to ask.

As for needing less flow - OK - y'all have me convinced! Thanks for all the input. As soon as I receive the tank, I'll play around with splitting a Dart's output between the display, fuge, and frag tanks and see how it goes. Does that make sense?

 

[Elliott]

<a href=showthread.php?s=&postid=13572579#post13572579 target=_blank>Originally posted</a> by GlassReef
Thanks for mentioning that - I was just going to ask.

As for needing less flow - OK - y'all have me convinced! Thanks for all the input. As soon as I receive the tank, I'll play around with splitting a Dart's output between the display, fuge, and frag tanks and see how it goes. Doses that make sense?

yep, makes sense

 

[wmilas]

I want to second (or third) what was said. Match the flow through your sump to that of your skimmer. Don't flow a massive amount through your fuge or you could end doing more harm than good (if it looks like a jacuuzi in there with bubbles its too much

Running 2 darts through a 75 gallon sump and you are also going to have micro bubble issues since the dwell time of the water in the sump will be close to non-existant.