Brian wea
Active Member
I have a 90 gal tank I'm about to start. I plan on buying an eheim pump for. My sump is a ruby 36 elite and has a volume of 41 gals.. do I want the pump to be 900 gph or the total volume of 1300 gph?
Question about pumps and volume
- Thread starter Brian wea
- Start date
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depends on the turnover rate you want.
vol x 10 or vol x 5
my x10 (as was SOOOO) reccomended is to fast for my 55g and smaller sump.
Im going DC variable next time.
bobman
Well-Known Member
It really don't make a difference I use tank volume but if you used system volume it will not hurt anything
ReeferBob
Valuable Member
Don't get stuck on tank turnover rate. It isn't as important as you think. If you go with a full siphon drain system (Bean) you will be fine for a 90. The pump I specified will be perfect. In most cases you are constricted by max flow rate of your drains. If you do not go full siphon, there is only so much you can flow before you get flushing and a lot of noise. If you go full siphon, you just need a pump that will keep up with that. There is no in-between.
system volume. for the correct math. (you probably dont want 10x) but the math is the same regardless. 90 + 40 x rate = gph
is that just because its a variable flow rate? sounds like its playing by ear. honestly curious you tecnique.
In most cases you are constricted by max flow rate of your drains. If you do not go full siphon, there is only so much you can flow before you get flushing and a lot of noise. If you go full siphon, you just need a pump that will keep up with that
I thought you calculated turnover so you match the flow rates of all the components.
ReeferBob
Valuable Member
On a 90 whatever you do will be enough. If you were at a 240 or bigger tank, then start to think about ways to increase/balance flow rate. But of course you would have 2 drains or more at that point and/or larger drains. But for your little 90, you don't need to worry about it. A single 1" drain running at full siphon is more than enough for your needs. It isn't a contest to see how much you can flow through your sump. There are advantages to high and low flow rates.
Also not sure what components you are talking about. If you mean the skimmer, the skimmer rate and abilities is not directly related to your sump flow rate. It sits there and does its job it doesn't matter if the rate through the sump is high or low.
The above is especially true of low volume systems like you are running. The little extra volume you are adding with your sump makes your sump great for hiding your heaters and skimmers and 10 pounds of rock but not much more. IOW it is not integral to the health of your tank like say a 120 gallon sump on a 240 gallon system.
mcarroll
10K Club member
Without going for overkill, the rate you probably want to shoot for is between two times (2x)and four times (4x) your displays volume in gallons per hour.
90
x2
=180 GPH
x4
=360 GPH
More is likely to be a bother and cause problems and brings you practically no benefit. Achieving additional flow in the tank is much better done with powerheads.
That number will be the actual flow rate - as calculated by a head loss calculator or as actually measured by you with a bucket - not the nominal flow rate that the pump or drain are rated for.
90
x2
=180 GPH
x4
=360 GPH
More is likely to be a bother and cause problems and brings you practically no benefit. Achieving additional flow in the tank is much better done with powerheads.
That number will be the actual flow rate - as calculated by a head loss calculator or as actually measured by you with a bucket - not the nominal flow rate that the pump or drain are rated for.
Hi Bob
By matching components, I mean the overflow skimmer box, drains, and return plumbing. If the math isnt done its pretty easy to overwhelm the overflow and you'd wind up choking the return pump, in my case it got loud and its not good for the pump for a lot of other reasons. On the other end if you have a single return in the tank it can become a jet.
Ive seen this prob a bunch here and with my local group forum.
Trust me I'm not racing my return rate. I do notice its doesnt have enough time in the sump to settle in the skimmer chamber and the fuge & return water has more particulates in it.
I was pretty bummed on my return rate at first as if you google get the reccomended from pump manufactuers and the calculators, not "opinions" 10x its Recommended
. So I wound up with a jet in tank and fortunately I did do good math and got a Overflow box rated for the pump.( I also got the box as it has a larger wider surface area for better surface skimming).Thank goodness DC is here, not sure why it took so long, so its an easy adjustment rather than choking. With the easy math and the easy to balance nature of the DC pump, it turns into a no brainer.
IMO with a too high return rate theres not enough time to effectively skim and settle in the sump, with too low a return there's not enough flow to get the particulates out of the DT into the filter.
For the OP(if you havent lost interest )maybe this is my OCD or engineering style, builds the system on the highest returnrate (10x)(based on total volume, and throttle back(dc) to achieve the a lower rate(4-7) depending on how the system performs.
Plus on cleaning day or emergency you can crank up pump to clear the water out fast from the DT.
For Bob and Mcarrol, is there an engineering and siphon prob with underrating the system this way. I haven't experienced it.
And Bob I think we both agree on the DC pump, yea prob a 5000, a 3000 would work but, but we can all do the math on that
mcarroll
10K Club member
I wouldn't lose sleep over minor discrepancies, but I actually would roughly match my skimmer and sump flow rates.
2x - 4x is a decent metric for both - maybe up to 5x if you wanted to oversize things a bit.
Matching the sump flow to the skimmer flow is what theoretically "keeps the sump fed" with fresh/nasty tank water.
Take @Brian wea 's 90 gallon.
2x - 4x is a decent metric for both - maybe up to 5x if you wanted to oversize things a bit.
Matching the sump flow to the skimmer flow is what theoretically "keeps the sump fed" with fresh/nasty tank water.
Take @Brian wea 's 90 gallon.
- We already know I'd be looking for an actual flow rate through the sump of between 180 gph and 360 gph....a little more wouldn't hurt. 5x would be (90 x 5 =) 450 gph.
- Tunze's 9410 skimmer would be one of my top picks for a skimmer. It has water flow rating of about 240 gph. Right on!
- AquaC's EV120 would be another top pick for me. It's default recommended pump is a Mag 5....no more than 450gph in operation. Excellent!
