Milwaukee 716690 Digital pH Controller - Accurate pH Measurement for Hydroponics, Aquariums & Water Testing | Perfect for Home Brewing, Labs & Pool Maintenance

This works extremely well on for controlling my CO2 injection on my 120g planted tank. It was easy to calibrate and install and is giving accurate readings so far after 1 week. This product gives real-time readings and has eliminated pH testing and that in its self is worth it to me. I have a timer plugged into the outlet that the unit controls. In my opinion, buying a timer with this is a must. It allows me to leave the product on 24 hours per day while letting the timer control the flow of CO2. I am able to monitor the pH at all times and evaluate the pH swings with CO2 injection. Currently, the pH is 6.8 in the AM before the CO2 comes on and it drops to 6.6 by the end of the time I have the CO2 set to be on. Works like a charm.