Milwaukee Instruments MC122 pH Controller

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.

This is the first PH monitor I've used and so far seems to be accurate. The label marks for the PH dial setting are a bit off. Only took about three tests to get my settings where I want them. One thing, it failed to trigger my CO2 twice while I had it plugged in directly to the controller. Inserting a power strip between the controller and the CO2 seems to have fixed this. Not sure if it's the CO2 or the PH monitor.

Only 1 set of packages for calibration supplied (as per photo in ad), but no Electrode Rinsing Solution or Electrode storage solution. These are optional, so plan to spend more for the solutions required for calibration, initial use, storage, or DIY. I interfaced this controller with the Milwaukee MP 810 dosing pump, bought separately. Recommend buying the unit together for about $2.15. I calibrated the electrode, which was spot on out of the box, gave it a test run. Pump delivers 60cc/3 min. I put the pH probe, and PH solution delivery tube from the pump in my 45 gal hydroponic garden's reservoir. I diluted pH DOWN solution 1/4 cup/gallon of water, and put the intake tube and filter (float?) provided with the pump in the diluted pH down solution. Set the dial on the controller to about pH 5.9, and put the toggle on Below. Setup this way, the controller will activate the pump to deliver acid to the reservoir to keep the pH below 5.9. The pH was above 6, and the pump immediately activated and pumped a couple of ounces of the acid solution into the reservoir, then stopped. Unit is on and will monitor pH and deliver enough acid solution to counteract the tendency of pH to rise as plants use up acid nutrients. What a relief! No more tedious pH checks and estimated additions of acid to keep pH in desired growth range of 5.5-5.9 for the heirloom tomatoes I am growing indoors.

Using this as a PH controller for a calcium reactor on a 105 gallon reef tank. Easy to install and great instructions for setup. I love having this controller and it allowed me to identify (before I started using within calcium reactor) that I had excess CO2 within my fish room and I was able to open up the room and increase water surface aeration to allow more fresh air to enter and increase my ph from 7.4 to 8.1. This is huge considering I could see the PH digital feedback during my root cause period for understanding why my 2yr+ reef tank had a low PH. I recommend this to any serious reefer.

Super easy to set up, seems quite accurate, and having a constant monitor is very nice. No issues at all. I used a previous version for monitoring CO2 in planted aquariums and had great luck with that as well. Glad I chose to revisit this manufacturer. =)

So far so good. Have had this for about 6 month's and it works perfectly . Oh just fyi, you only need one. If you try to use 2, one for up and one for down. They will fight each other. It can do both up or down. You should not have large Ph swings if you do you possibly do not have enough Cal-mag to act as a buffer from fluctuations. It's a bit expensive but not having to worry is worth a lot. ;)

Have to say I was a little apprehensive to order this based on some of the comments, but very happy to report it works flawless... After calibrating the probe using the supplied fluids, I tested it against a reliable PH test kit and it was Spot-On.. I use this in conjunction with the Milwaukee CO2 regulator with great results... Since I didn't purchase the regulator from Amazon I will have to rate it here. - A lot of comments about the Milwaukee CO2 regulator are not good, but if you take the time to let the low pressure side break in a while "I let mine bleed into the air for 3 days prior to putting it into service" the pressure settles in nicely and the flow rate can be fine tuned with the valve rather than the regulator. It's running a 90 gal planted tank with fantastic results.

After calibrating the unit seems to be holding the calibration really well. It was easy to install and operate. I am having a problem though. The unit says it is activated but the relay is not tripping. I don't know if it is a faulty relay or if it is the unit itself. The unit will work for a day or two if I reset it but will stop working after that. Luckily I have a really stable aquarium and this is more of an added layer of protection, but this could be detrimental for anyone relying on it. I will reach out to Amazon to see about a replacement. I will update this review if I get positive results.

Works perfectly with my co2 system but if you buy this from amazon.com the American site you will have to swop the (110 volt) 12 v 500ma power adapter for a (240 volt U.K.) 12 volt 500 ma power adapter with the end plug you can turn to get the right polarity and a travel adapter for the socket that you plug you co2 into So have given 4 stars because the voltage supply is not universal

Ottimo prodotto di fattura eccellente e sonda molto precisa, le prime volte va controllato per poterlo calibrare al meglio poi va da Dio, consigliatissimo

Muy buen controlador, muy preciso, sin duda lo recomiendo.

Works great with CO2 system .. no need to worry about switching off the CO2 system ..