How do I check my flow?

[jimeluiz]

How do I get an update on the flow in my system? Our set up is a little more than two years old. We have a 58 gallon tank with a sump that has about 15 -20 gallons in it. Our pump, a submersible Aqua-Globe 6000 is rated to 850 gal/h, but with the rise back up to the tank at about one meter I think the optimal flow is more like 600+ gal/hour, as per the chart that came with the pump.

There is a split return (“T” not “Y”) with two outlets back into the tank. I have never dismantled the return tubing to clean out any slime that may be in there. They are opaque so algae should not be in residence. I posted about a year ago asking about cleaning out the tubing and folks suggested then that it was fine…

I have one Maxi Jet 1200 powerhead. We do periodic scraping of coralline out of the intake cage.

At the time we set things up this seemed to provide plenty of flow for our softie tank. Now in my efforts to battle a persistent cyno situation I’m thinking maybe my flow rate has sagged a bit.

How can I tell? Thanks.

 

[Jerome]

Eric Borneman says:

low flow 1-5 cm/sec
med flow 6-20cm/sec
high flow 21-50cm/sec
very high flow over 50cm/sec

so when you feed you tank look at the particle and the speed their traveling in your tank. You be able to guesitmate using this to figure low-high flow areas on the tank.

 

[Warnberg]

Here is a head loss calculator.... sorry that it's from anohter site but hey hope it helps.

http://www.reefcentral.com/calc/hlc2.php

 

[Kensn]

I would look at 2 things first. Is the flow entering your tank set up so that it creates good movement in the tank, and what is fueling the cyno.

 

[KimPossible]

I would work the "headloss calculator". You'll get what your looking for.

 

[jimeluiz]

Thanks all. I'll try redirecting my returns to change things up and see if I can tweak the movement some.

The headloss calculator has a drop down menu of pumps and mine is not on it. I suppose I'll have to look up each one to see which one has the same g/h mine does.

I'm also wondering if over time my pump would drag or if the tubing ever needs a cleaning...

 

[dwall174]

Well I’m not sure if this was the right way? But I think it worked out ok for me!
What I did was to place two flexible lines on both of my inlets to the tank. I then ran these lines into a 5 gal container, I let the pump run for only ten seconds. In that time I got a total of 268 ounces of water, So 268 ounces in 10 seconds x 6 = 1608 ounces per minute. 1608 x 60 = 96480 ounces per hour. Then I just divided one gallon 128 ounces by 96480 which gave me a figure of 753.75 GPH
I also did the head-loss calculator & came up with 812 GPH! So my math seems to work out good enough for me!