Milwaukee Instruments MC122US pH Controller with Hi/Low Range Alarm, 2 Point Manual Calibration, 0.0 to 14.0 pH Range

This is a must have for my aquarium CO2 setup. Literally shuts off my CO2 solenoid once the PH reading on my Milwaukee controller hits 6.9. Easy setup and calibration. Maybe I am using it wrong, but I do wish the suction cup ring that hold the wand in place was more able to keep the wand in the desired position which I like the vertical position. Great product over all and I highly recommend it!!!

I currently have 2 of these controlling ph in hydro reservoirs. They work just fine for my 30+ gallon reservoirs. Really makes it nice having steady control over ph.Been using them for 6 months or so and oh probes seem to hold calibration as well. I’m sure eventually I’ll need to replace the probes but that’s to be expected. Great value and worth every penny.

The PH Controller works best and I am very satisfied with the performance, but the included AC/DC adaptor after checking with my multi tester gives an output of 19.78volts which is over than the required voltage of the main unit, instead of 12volts only. Amazon help center assist me to solve the issue.I am happy with performance of this product and it makes my life easy and no worries while I'm away.I also suggest that the included AC/DC adaptor should be auto volt since this product is sold internationally, considering the output voltage is 12volts only to prevent sure damage to the main unit.

After having all kinds of shipping issues to get it to me it finally showed up. The box looked like it had been open before. The product was missing the probe and when I tried to power on the unit it did NOT power on. The unit is used, broken and missing the probe. This must be some twisted joke. Unbelievable! Waiting on a replacement.

Just hooked it up to my reef tank, so not a long term review. I was using a Hanna PH portable meter that was about the same price as that. My readings were all over the place, even after replacing the head and calibrating before each uses. Would start around 6.5 and climb to 7.1 for a few min during the ATC, and then keep climbing to 8.3 over the next ten min.This came dead on out of the box at the 7.01 and 4.01. As soon as I put the prob in my sump it was 8.1 and stayed there.I have it controlling a motorized ball valve that bypasses my skimmer's CO2 scrubber and toggles my kalk stir top off relay on and off. If PH > X then open bypass to CO2 scrubber and open relay trigger to cut kalk top off. I have my RODI top off sump float slightly lower than the kalk sump float. I also dose two part so I can peg the PH at where ever the controller is set.Highly recommend 👌

I purchased this so that I could monitor the PH levels in my hydroponic system easily, rather than pulling out the testing kit and taking a sample several times a day. It worked so well just for monitoring, I decided to get a pump to automatically add either ph up or down. You can only choose one, but I found that my system likes to drop below 5.9, so I mainly use ph up to keep it between 6.0 and 6.2. I didn't use the Milwaukee pump for $80, however. I got a generic $12 pump and used an old mobile phone charger for power. Works great and I no longer have to make quick adjustments to keep it in range. I no longer wake up on the morning to a ph pf 5.1 :)

Does exactly what it is supposed to do. Using to control the flow of CO2 into my aquarium. Shuts down the flow of CO2 at the desired PH level and back on when the PH level goes back up. It should make the CO2 tank last longer as it is shutting down approximately 2 hours of the 7 hours that I am running CO2 into my tank. I did need to purchase a digital timer to connect to the CO2 regulator solenoid as the analog timer was also shut down by the PH controller, making the time of day off by 2 hours every day. Would highly recommend to anyone running pressurized CO2 in an aquarium

Amazing product, my fish tank has become much more stable. Also very simple to calibrate.