Aquaponics Monitoring Project

My school is doing an aquaponics project and one of the teachers in charge has asked me to help her with the monitoring of the fish tanks. The prime objective us to monitor the dissolved oxygen and carbon dioxide levels in the water tank. I looked through Amazon and the Adafruit website for these sensors, but could not find anything. Any ideas? My main concern is finding the right sensors with proper connection pins. The teacher wants to save money, but is willing to pay more for better quality.

The tanks are 20 gallons tanks.

Antioch27:
My school is doing an aquaponics project and one of the teachers in charge has asked me to help her with the monitoring of the fish tanks. The prime objective us to monitor the dissolved oxygen and carbon dioxide levels in the water tank. I looked through Amazon and the Adafruit website for these sensors, but could not find anything. Any ideas? My main concern is finding the right sensors with proper connection pins. The teacher wants to save money, but is willing to pay more for better quality.

The tanks are 20 gallons tanks.

Welcome to the Arduino forum.

I asked Google "how to monitor dissolved oxygen arduino" and got back very detailed answers. You can probably do the same for carbon dioxide levels.

Paul

Dissolved oxygen is straightforward: use a DO probe, similar to pH probe. Connects to pH sensor boards just the same.

You may also want to look in to ORP (Oxydation Reduction Potential), also commonly used in water quality monitoring related to fish.

Dissolved CO2 is a whole different thing: in solution it's turned into bicarbonate (HCO3-), lowering the pH slightly in the process. pH in turn is something that's easy to monitor, the carbonate ions not. I've also never heard of the need of monitoring CO2 in aquaponics - normally pH, EC, various ions such as nitrite and ammonium.

I must add I'm more into hydroponics than aquaponics so never dealt with keeping fish in depth, but out of interest (it's a closely related subject) I've been looking into it a bit.

wvmarle:
Dissolved oxygen is straightforward: use a DO probe, similar to pH probe. Connects to pH sensor boards just the same.

You may also want to look in to ORP (Oxydation Reduction Potential), also commonly used in water quality monitoring related to fish.

Dissolved CO2 is a whole different thing: in solution it's turned into bicarbonate (HCO3-), lowering the pH slightly in the process. pH in turn is something that's easy to monitor, the carbonate ions not. I've also never heard of the need of monitoring CO2 in aquaponics - normally pH, EC, various ions such as nitrite and ammonium.

I must add I'm more into hydroponics than aquaponics so never dealt with keeping fish in depth, but out of interest (it's a closely related subject) I've been looking into it a bit.

Yes, it is nearly impossible to measure CO2 in water electrochemically. It has been a point of research that nobody has solved for years and years. The person who solves it will make a lot of money because if you know CO2 and pH you can calculate alkalinity and salt water aquarists would pay good money for a way to automatically control that.

Thanks! I will review this with the teacher and see how the project changes.

I had a similar requirement and I found out that Atlas Scientific Sensors have a problem in configuration and accuracy:

https://forum.arduino.cc/index.php?topic=487535.0

Instead I would be going for this one instead

Looks much more reliable