Determining max flow rate for tank?
- Thread starter PCygni
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OP
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PCygni
Active Member
I'm not really looking for a precise calculation -- just wondering if there is a quick rule of thumb that applies. I would really like to maximize the flow through the system but don't know how many gallons an hour the drainage pipe will be pulling out of the tank.
frankdontsurf
Community Member
http://www.reefcentral.com/index.php/drainoverflow-size-calc
In tank you want 10-20x = "medium flow" and 40x+ = "high flow", low flow = deadest spot in the tank
Palting
Active Member
The Marineland tank standard overflow has a maximum capacity of 750gph. Beyond that it will start surging
pickupman66
5000 Club Member
shoot for 8-10X the tank volume to flow thru your sump.
DaveMorris
MACNA2016 Co-Chair
There are a lot of differing opinions on flow through your sump. Are you running a filter sock in your sump? If so I would get as close to 750gph as I could. More flow through a sock means more filtering of the water. If you do not use a sock then it is kind of a waste to do much more than your skimmer can handle.
shovelrider
Active Member
This is a highly debated topic!
3x tank volume through sump. 7-11 x tank volume circulation in main display.
Max flow depends on if you run a gravity drain or full siphon, full siphon will handle a considerable more amount of flow than gravity drains.
3x tank volume through sump. 7-11 x tank volume circulation in main display.
Max flow depends on if you run a gravity drain or full siphon, full siphon will handle a considerable more amount of flow than gravity drains.
Kworker
Tang Lover
I find anything from 4-6x is adequate by default.
Why?
Because your skimmer pump of course increases with size. My 55gal runs 250gph through the sump because that is about what the skimmer is rated for.
In reality all you need is to match your skimmer, what benefit is there to go beyond that?
Can't say for flow, you shouldn't be looking to fulfill your tanks flow that way it, just use powerheads.
Why?
Because your skimmer pump of course increases with size. My 55gal runs 250gph through the sump because that is about what the skimmer is rated for.
In reality all you need is to match your skimmer, what benefit is there to go beyond that?
Can't say for flow, you shouldn't be looking to fulfill your tanks flow that way it, just use powerheads.
OP
OP
PCygni
Active Member
Thanks for the responses. As per usual, every answer opens up a 1,000 more questions: what are your guys feeling on filter socks? I plan on getting a trigger systems sump that comes with a bulkheads and socks. Is it worth running the socks? I hear a lot to contrary, but am currently thinking of getting several socks and using them.
gonpostal
Community Member
I don't use the socks because they're too high-maintenance IMO. When I do a water change I usually use a powerhead to blow any detritus off of the rock, and I stick some filter floss between the baffles in my sump and leave it there overnight to clear up the water. I have Trigger Systems sump BTW, love it.
A good rule of thumb is 3 to 5x the display volume for a return pump and anywhere from 10 to 50x or higher for your powerheads or internal circulation depending on your corals and needs.
I tend to lean towards the 5x or a little higher after headloss for the return pump depending on the size of your sump, baffle arrangement and type and size of skimmer. You don't want the velocity to be too high in the sump or your skimmer will not be efficient and you run the risk of carrying microbubbles back to the display tank. A flow of 500 +/- GPH after your calculated headloss is probably about where you want to be. You can purchase a pump slightly larger and install a valve on the discharge side to fine tune or throttle the flow and is commonly done.
I don't use filters socks myself. I have areas in my sump where the detritus collects and I pump it out with and old MJ powerhead with a piece of tubing on it or vacuum it out with a shop vac during major maintenance which is rare.
I tend to lean towards the 5x or a little higher after headloss for the return pump depending on the size of your sump, baffle arrangement and type and size of skimmer. You don't want the velocity to be too high in the sump or your skimmer will not be efficient and you run the risk of carrying microbubbles back to the display tank. A flow of 500 +/- GPH after your calculated headloss is probably about where you want to be. You can purchase a pump slightly larger and install a valve on the discharge side to fine tune or throttle the flow and is commonly done.
I don't use filters socks myself. I have areas in my sump where the detritus collects and I pump it out with and old MJ powerhead with a piece of tubing on it or vacuum it out with a shop vac during major maintenance which is rare.
Planedoc
Active Member
Correct answer for return pump is 3 to 5 gph times total water volume. Make sure you lay out your plumbing to account for head pressure. "head pressure is not the height from sump to display but a combination of height + every foot of pipe every fitting and every valve as all reduce flow. Once you have that figured out add a little extra so you can power a reactor or three in the future. It's easier to restrict the flow on and pump with a gate (preferably) or a ball valve on the outlet side of your pump than it is to buy a bigger pump later. The in tank flow of 20 to 50+ gph X tank volume can be done at a fraction of the cost with powerheads . Your sump adds water volume, gives you a place to hide equipment, and maybe have a refugium and filter socks. It's not meant for flow. So like others said anything more than what your skimmer can handle is overkill and a waste of money.
Rjramos
Valuable Member
I run a single blueline 70 which does about 1750 gph on a 120 gal. I move the tank volume app. 8x/hr and feed an MRC M-1 skimmer which requires 750gph with this single pump. No powerheads or additional pumps in the display. The double overflows(1"-bulkhead outlets), gravity feed into a refugium and the return sump setup under the refugium. The refugium also gravity feeds into this lower sump. This has worked great for many tank builds I have done for many years. The only con is that in order to do this method , your cabinet has to be at least 36-40" tall, in order to accomadate the refugium above the main sump.
