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Raul-7
01/23/2015, 10:33 PM
http://www.amazon.com/Milwaukee-Economy-Portable-Dissolved-Calibration/dp/B007Z4KKIQ/ref=lp_5088419011_1_1?s=industrial&ie=UTF8&qid=1422077365&sr=1-1

Has anyone used this meter before?


I was curious about measuring the DO levels during certain parts of the day.

bertoni
01/23/2015, 11:38 PM
At the very least, you'd need to compute a correction factor for ocean water. The meter might not work in seawater very well at all, though. I'd contact the manufacturer.

I used the Salifert oxygen kit, and I never saw a measurement from the water column that was anything other than fully saturated. Does your tank have a skimmer? Is there a specific problem you're trying to solve?

Raul-7
01/23/2015, 11:43 PM
Just curiosity. :)

bertoni
01/24/2015, 12:51 AM
Ah, okay, I can't blame you for that. I have the same tendency. :)

billsreef
01/24/2015, 07:17 AM
Based on the type of probe, it will work in SW. However, to get an accurate % saturation you would need to correct for salinity and temperature. Fancier (and more expensive) meters include temperature and conductivity, and also make those corrections themselves.

Raul-7
01/24/2015, 12:02 PM
http://i24.photobucket.com/albums/c28/Raul-7/xingu.png (http://s24.photobucket.com/user/Raul-7/media/xingu.png.html)

How is what saturated at 110% with that temperature? Does depth play a role?

bertoni
01/24/2015, 04:11 PM
I don't know enough about fresh water chemistry to say much. I could make some guesses, but I'd rather defer to someone with some background in that area.

billsreef
01/24/2015, 06:35 PM
Over 100% saturation occurs in areas of turbulent surface waters. Waves, rapids, etc. This occurs in both SW and FW.

Raul-7
01/25/2015, 03:21 AM
Makes sense; so areas next to the coast have higher O2 levels

billsreef
01/25/2015, 09:04 AM
Doesn't have to be next to the coast, just needs to be the surface with some decent wave action. It's also possible to have anoxic surface waters in areas of high eutrophication in some coastal ares due to pollution....i.e. lots of nutrient runoff and sewage.

Raul-7
01/25/2015, 08:45 PM
So turbulent water is better at adding DO than say photosynthesis?

bertoni
01/25/2015, 10:44 PM
That's a good question. I'm not sure. Photosynthesis probably could drive supersaturation if the process didn't become carbon-dioxide-limited first.

billsreef
01/26/2015, 04:54 AM
So turbulent water is better at adding DO than say photosynthesis?

I've never seen supersaturation of O2 from photosynthesis in natural waterways, however, I've seen it plenty of times from turbulence ;)

It's one of the reason bioballs work so well at oxygenating water, protien skimmers do as well, it's the key competent to oxygen reactor, etc.