Turn Over

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Scuba Steve

Member
No I don't mean in the bed lol. Rather I am referring to the rate at which the water turns over in my tank. I have been doing a little research and am just seeking some confirmation. My tank is approx. 190 gallons in volume. Am I right to concur that if my return pump is operating at about 700GPH and I have 5 powerheads, the output of each individual ph being 350gph, then my total turnover is equal to about 15x and therefore about right for a fowlr tank.
Phew!!! Hope I explained that right

Regards

Steve
 
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DaveK

Well-Known Member
It depends on who's counting.

I would only count the water that runs through the filtration system, and I would not count the water flow generated by powerheads, closed loops and so on. In other words, only water that gets processed gets counted, not water that just gets moved.

By my method of counting, you are using a pump of 700 gph on a 190 gal tank for a turnover rate of only about 3.7 times an hour.

I would consider this far too low a turnover rate, and I would either add a second return pump at 700 gph or replace the pump with one that can pump at a rate of 1200 - 1400 gph.

Other people might do the counting differently.
 
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Scouter Steve

Active Member
Your water flow is almost 13X, turn over is about 3.6X. Depending on what you are doing you might be fine. Flow through a sump at 3.6X is OK. Might want more movement in the tank.
 
blue_eyes53813

blue_eyes53813

Well-Known Member
Very interesting.. I just added my sump and refugium a month or so ago.. I had major waterflow issues and algae/bacteria problems as well.. My turn over rate with just the powerheads must of been very very low if nothing at all... It makes sense that they dont really move alot of water. Since the addition of sump and refugium and about 10x the flow the algae is almost gone.
 
BigAl07

BigAl07

Administrator
RS STAFF
blue_eyes, I think just adding "movement" is the key to how you solved your algae problems. Stagnation quickly leads to algae "bloomation". Get that water moving and your chances of a heavy algae outbreak is greatly reduced!!

Turn over, IMHO, relates to how often the water is actually "filtered" if there is a machanical/chemical filtration attached. Now if you're running no additional filtration other than LR then flow = turnover.. I think.. :LOL:

Allen :)
 
Woodstock

Woodstock

The Wand Geek was here. ;)
RS STAFF
Steve, that is how I count 'total turnover' also. It is all flow within the tank... return/ph/etc.

My return pump from my sump/refugium is about 850 gph which equates to 5.6 times turnover for my 150 gallon system; with the two korallia#3 (on random wave timers) pushing 850gph each, I end up with a turnover rate of 5.6, 11.3 or 17 times per hour (depending when the PH are on).
 
Woodstock

Woodstock

The Wand Geek was here. ;)
RS STAFF
The rock and sand in the display are part of the filtration system so why eliminate the flow there from the equation??

If we're counting "turn over" as only water that runs through a mechanical or chemical filter, then I would only count the output of my skimmer and two phosban reactors... that wouldn't be much at all.... 4 times per hour.
 
BigAl07

BigAl07

Administrator
RS STAFF
Woodstock said:
The rock and sand in the display are part of the filtration system so why eliminate the flow there from the equation??

If we're counting "turn over" as only water that runs through a mechanical or chemical filter, then I would only count the output of my skimmer and two phosban reactors... that wouldn't be much at all.... 4 times per hour.
Click to expand...

Hence why this is such a fascinating and "educational" hobby. I agree with LR and LS being present then you can, at least to some degree count that as tank turn over. Let's get hypothetical for a moment and see if we can agree to disagree *grin*

Let's say it's a brand new tank.... 190g and 220 lbs LR (which will become the filtration system once established). He has 700gph going through a sump/fuge 1750gph merely being "moved" around within the tank. IF he's worried about making sure the entire system is passed over the filtration system then he's way understated....The "tank" is only passing through the filter 3.7x per hour. In that scenario my original numbers are indeed accurate.

Change just a couple of the elements (LR established and tank fully cycled) and your numbers are dead on. I still like to see move total tank volume passing through my "other" filtration system than just 3.7x/hr. I like the idea of having lots of water cycled through the alternate system which tends to (not always but usually) create fewer stagnation pockets. The power heads inside the display do make a HUGE contribution to any tank but personally I like to move the contents of the tank OUT and over additional filtration and then re-introduce it into the tank. Maybe that's just my hillbilly justification for My refugium..

Allen :)
 
sasquatch

sasquatch

Brunt of all Jokes~
PREMIUM
Oh Dear, I think that too much flow THRU the fuge is not good as it requires some dwell time for cleaning, Hi flow in the display tends to keep everything in suspension with the hope it gets to the sock and out out out, I would like a BB but dont like the look
 
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boozeman

Well-Known Member
correct, my folically gifted friend...thru the sump it is best to keep it at about five times turnover so that the skimmer can do its thing. Flow in tank depends on what you keep 15-20 times turnover tends to be the norm there
 
sasquatch

sasquatch

Brunt of all Jokes~
PREMIUM
UMm so with return pump, powerheads and closed loop I have4300gph , 80gal display thats what in turnover, 53.75x ?? that cant be right(curse Hi Math damnit)
 
Woodstock

Woodstock

The Wand Geek was here. ;)
RS STAFF
sasquatch said:
UMm so with return pump, powerheads and closed loop I have4300gph , 80gal display thats what in turnover, 53.75x ?? that cant be right(curse Hi Math damnit)
Click to expand...

:eek: That is like a gym for fish. A water treadmill! LOL.. I'll send mine to you if they get overweight :D
 
sasquatch

sasquatch

Brunt of all Jokes~
PREMIUM
See, there is a description only, 80 % of this flow is buried in the LR, the water column is moving, the fish never get blown around and the water is always full of suspended matter. How does flow relate to this?
 
B

boozeman

Well-Known Member
another well made point. Flow is ever changing. As corals grow, power heads must be re-positioned for better flow.
that is why it is not a good idea to bury powerheads into your live rock display
 
iamkellogg

iamkellogg

Member
This is very interesting. It gives me something else to think about while I am stressing out over my water flow and coral growth. ;)

Kelly
 
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