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Dissolved Oxygen Testing

Bradders

Bradders

Member
Joined
11 Dec 2023
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808
Location
United Kingdom
Hi Everyone,

Keen to understand my aquarium's dissolved oxygen levels and CO2 levels.

Any recommendations on a good pieces of kit to do this which do not fall into the 'impossible to read' category?!

I did have a search online, then thought I was better off asking people who live and breathe this!

Thanks in advance.
 
BRJP1 said:
Hi Everyone,

Keen to understand my aquarium's dissolved oxygen levels and CO2 levels.

Any recommendations on a good pieces of kit to do this which do not fall into the 'impossible to read' category?!

I did have a search online, then thought I was better off asking people who live and breathe this!

Thanks in advance.
Click to expand...

On the DO side, I've looked at these in the past:

This for a non-logging one:

www.test-meter.co.uk

Extech DO210 Dissolved Oxygen Meter

Extech DO210 Dissolved Oxygen Meter The Extech DO210 Dissolved Oxygen Meter is capable of measuring dissolved oxygen and water temperature. Dissolved oxygen can be measured in absolute terms from 0 to 20mg/l with accuracy of ±0.4mg/l or as a percentage of oxygen capacity from 0 to 100% with...
www.test-meter.co.uk www.test-meter.co.uk

and this for a logging meter so you can extract and graph data:

www.test-meter.co.uk

Extech SDL150 Dissolved Oxygen Meter Datalogger

Extech SDL150 Dissolved Oxygen Meter Data Logger The Extech SDL150 Dissolved Oxygen Meter & Datalogger accurately displays and stores dissolved oxygen readings, oxygen in air readings and temperature for a comprehensive overview of water quality. The SDL150 uses a polarographic oxygen...
www.test-meter.co.uk www.test-meter.co.uk

I've fancied having a DO meter for some time, but then I've always come back around to reality that I always do everything I can to maximise DO, so what will the meter really be able to do for me to aid my processes.
 
Wookii said:
On the DO side, I've looked at these in the past:

I've fancied having a DO meter for some time, but then I've always come back around to reality that I always do everything I can to maximise DO, so what will the meter really be able to do for me to aid my processes.
Click to expand...
_Maq_ said:
the cheapest among optical. I'll go for it when I get bigger.
Click to expand...
Thank you @_Maq_ ! Expensive!
Thank you @Wookii ! And agree, despite my technical brains need to know, I have questioned whether I need to!

So any suggestions on C02 reading?
 
Wookii said:
I always do everything I can to maximise DO, so what will the meter really be able to do for me to aid my processes.
Click to expand...
I can tell you that my stance about oxygen is identical but still I'd find DO meter very useful. Firstly, I'd map DO concentration in "normal" tanks during day & night. Then, I'd try to compare the effects of various aeration methods. Is my assumption that venturi is the best correct? I'd like to know. Thirdly, no matter how I try, incidents in my tanks do happen. Often simultaneously with temperature change, sometimes quite inexplicably. I would love measuring DO during these periods of crises, It'd tell me a lot about microbial life and other aspects of tank's well-being.

However, I don't recommend those membrane DO meters you've chosen. The membranes are expensive and need to be replaced quite often. The liquid is incredibly expensive. And the gadget as a whole did not impress me as very reliable. That's why I'd go for an optical meter. Alas, too expensive.
 
BRJP1 said:
So any suggestions on C02 reading?
Click to expand...

Personally I think it's difficult to beat an in tank drop checker, but that of course won't push out an accurate numerical value if that's what you are after. The only other way without incredibly expensive lab equipment is a pH meter, but again, that won't give you a direct measurement, and only estimates with some extrapolation and calculation.
 
_Maq_ said:
However, I don't recommend those membrane DO meters you've chosen. The membranes are expensive and need to be replaced quite often. The liquid is incredibly expensive. And the gadget as a whole did not impress me as very reliable. That's why I'd go for an optical meter. Alas, too expensive.
Click to expand...

Yep, the replaceable membranes put me off a bit too, and were another reason not to buy one, but if I were to get one, these membrane DO meters would be hard enough just justify the expenditure for on their own, so the optical ones would be well out of reach.
 
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Hi all,
BRJP1 said:
Any recommendations on a good pieces of kit to do this which do not fall into the 'impossible to read' category?!
Click to expand...
The problem with measuring dissolved gases is that all the kit is fairly expensive. That was why the drop checker and pH chart was developed to <"estimate CO2">.

In terms of dissolved oxygen meters, they are <"easy to calibrate and use">, the <"only problem is the cost">.

I'll add in @DeadFish as they are probably the best person to ask.
DeadFish said:
but I work in an aquaponics lab and teach aquaponics, so have access to equipment most do not.
Click to expand...
dw1305 said:
I'm actually trying to buy some more DO meters at the moment for work.
Click to expand...
Eventually I purchased a meter that measured pH, conductivity and dissolved oxygen (<"Hanna portable multi-parameter meter">). It has been good and reliable, but I wouldn't invest that amount of money (~£1600) just to use in the aquarium.

cheers Darrel
 
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dw1305 said:
Eventually I purchased a meter that measured pH, conductivity and dissolved oxygen (<"Hanna portable multi-parameter meter">). It has been good and reliable, but I wouldn't invest that amount of money (~£1600) just to use in the aquarium.

cheers Darrel
Click to expand...

Have you taken it home so measure the DO in one of your tanks Darrel? It would be really interesting to see the DO graphed over 24 hours in a low tech tank.
 
Instead of cancelling Christmas in favor of buying a piece of expensive measuring equipment :) DO can be determined fairly easily with a titration analysis. It may take a little bit of prior lab training and the precision is not great but should give you a fairly good ballpark idea.

Cheers,
Michael
 
Wookii said:
Personally I think it's difficult to beat an in tank drop checker, but that of course won't push out an accurate numerical value if that's what you are after. The only other way without incredibly expensive lab equipment is a pH meter, but again, that won't give you a direct measurement, and only estimates with some extrapolation and calculation.
Click to expand...
No, I think that would be fine. Any recommendations? (I ask as, once again, I was finding it tough to find one with the solution and the dropper).
 
Hi all,
MichaelJ said:
but should give you a fairly good ballpark idea.
Click to expand...
This is the quick and dirty <"temperature - DO saturation"> chart.

nomogram-gif.gif

AlecF said:
That's my Christmas Day sorted, reading Darrel's report on his oxygen levels
Click to expand...
It honestly sounds better than <"my average Christmas day">. Unfortunately I'm visiting in-laws, so you will have to wait until the new year.

cheers Darrel
 
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