AC Infinity pH Meter PRO Kit, High Precision Digital pH Pen with ±0.01 pH Accuracy and Interchangeable Probe, Nutrient Test pH Meter for Water Hydroponics Plants, Gardening, Aquariums, Swimming Pools

Stays calibrated for a reasonable amount of time and works very well. I have no complaints at all.

The media could not be loaded. The item I received was used and damaged.

So far good, easy, and accurate. I didnt read any of the instructions

So I purchased the ac infinity pro ph meter kit and when I received the package I was completely stocked and couldn't wait to start using my new meter which was a huge upgrade from my cheap 10 dollar meter. Ok so fastworard a bit...... I get to opening up the package to find a really nice looking ac infinity package staring up at me through the top of the ugly plain amazon box with a nice dark black background and a huge photo of the meter on the front of it so you automatically know what's inside. I pull it up out of the box and could instantly feel the weight of the products and case. I tear off the outside cardboard sleeve and in front of me is an awesome storage case with the company name on top and 2 cheap little clasp to hold it shut but other then that the case is really a nice touch and really helps keep everything neat and in place. So I open up the case and there is my instruction book, my buffer mixes, some cool little containers for each of the buffer liquids when you are calibrating your meter, and a small bottle of storage solution for storing your meter and of course the meter itself. Everything was nice and organized and looked really good sitting there waiting to be used. I quickly got to reading the instruction booklet to get familiar with my new meter and once I felt comfortable enough to calibrate my meter I did just that. I started like the booklet said by soaking the probe in the storage solution for around 30 minutes. I then rinsed the probe in some distilled water and got out my buffer solutions and their little containers. I filled each container up around half full of each solution which is very easy and everything is already marked for you so there is no guessing or anything I then started in the 7 then the 4 and finally the 10 each time getting right on the money and getting my little smiley face confirmation on all 3 solutions. So my ac infinity ph meter is 3 point calibrated and ready to go so I go ahead and get my mixture mixed up and pull out my newly calibrated meter and gave it a test drive. The first time using the meter i got the readings I was looking for very quickly and very easily but....... there is always a but. The second, third and the fourth time using it something wasn't right. I kept the probe in the storage solution and only used distilled water for rinsing so I'm not sure what the issue is but anyways I just couldn't get a good reading. It would just keep bouncing around and would just keep dropping. I mixed my plant nutrients like always and already know around where it should be after mixing but the meter would drop slowly to where it should be but then it just keeps dropping and the smiley face shoes up but quickly goes away because it start dropping some the the smiley will come back for a second or 2 and then it drops more then the smiley comes back then it disappears and the numbers drop some more. I can never get a good reading. I ended up calibrating the meter again and it worked for 1 time great again then started acting stupid again. I calibrated it again and the same thing it worked good and fast again. So I guess if you want a fast accurate reading you have to calibrate it every single use even thought I use it almost daily but definitely every other day and I keep it in the storage solution so it isn't drying out or anything I don't know I am pretty upset with this purchase. I think they should give you more storage solution too because mine is almost gone already but it says to store it in the solution so that's what I've done. It seems really well made and really heavy duty and reliable but for some reason it's looks was deceiving for sure. I do believe the temp on the meter is pretty accurate but the ph number isn't unless you calibrate it before every use. If I have to calibrate this thing everytime I want to use it I think you should send me a lot more buffering solution. I think for the cost it is great the only complaint is that it doesn't stay calibrated and that is a big big bummer. I know you have to recalibrate it every once in awhile but everytime is ridiculous I think. I wish I would have picked a different one now which stinks because I actually did think I found a really awesome meter that I would be really happy with and instead I got stuck with a dud.

Great carrying/storage case. Amazing poem. Functionality is great. The fact that it comes with calibration and storage solution vials that fit perfectly is wonderful. No having to prop it up in a shot glass of storage solution like other pens. Removable/replaceable probe is such a smart thing to have unlike a lot of other pens that cost the same or more. Also it comes with 4.0, 7.0, and 10.01 ph calibration solutions unlike most brands that only include the 4.0 and 7.0 so let’s just say this device is superior in many ways. There is one that costs a little more but includes EC and TDS readings as well as the PH and Temp readout that this one utilizes. Highly recommend.