[vulcaner]

Hello there, I'm new in this forum and i don't have much knowledge in chemistry. I need help in a question that may help me a lot in my research "measuring dissolved oxygen for aquaculture purposes". The problem is that the sensors i need to measure the DO are too expensive and i need a more cheap and automatic way to do it. I was searching over the internet and found about other metric, called Redox, which is related to the Oxidation-Reduction Potential (ORP). Then i thought that maybe this metric could be used to measure the DO, because both are strongly related to the oxygen. Does this make any sense?

Sorry my lack of knowledge, but i didn't know where else to find help. Thank you for anyone available to help.

[Borek]

I am almost sure some of the sensors on the market are ORP.

[Enthalpy]

What is "too expensive"? If you spend a few hours on this problem, your time is more expensive than this sensor
https://www.dfrobot.com/product-1628.html
No idea how good it is.

[vulcaner]

The sensor will be placed for measure the DO of a fish tank. The idea is to control the DO levels using a aerator, based on the previous readings. The major problem isn't the price, but the lifespan of the sensor. I read in some article that in about 6 months his readings will no be very precise anymore, and I'll have to buy another, which will make the costs of the project too high.

I thought about the measurement of DO using Redox in this site: http://www1.lsbu.ac.uk/water/water_redox.html

[Borek]

Platinum will work forever, reference electrode is the weak point.