HMDPHM80 Digital pH/Temperature Meter

If you have read any of my other reviews on PH (and EC) meters I have purchased, you'll know it has been a real frustration point for me to find a good one. I purchased three other PH meters from various manufacturers and none of them were dependably accurate and none could be calibrated easily if at all. They all cost around the same ($10-$20) operated about the same and appeared to all be built in the same factory but just branded differently and the housings were slightly different. For the most part they were clones. Even the instructions that came with the units were almost identical. The reviews were mixed too so it was pretty much a crap shoot. I finally decided to up the ante and spend a little more money (actually over two times as much), in the hopes I could finally find a reliable and easy to use model. I had already purchased an EC meter from HM Digital for the same reasons, and it has proven to be worth the extra money so I decided to try a PH meter from the same company. So far I have experienced the same positive results and have been using the meter for over two months. The meter operates very similar to the other models but is clearly not built in the same factory - the instruction sheet is a clear indication of that. It's much more detailed and actually makes sense when you go through the steps to use or re-calibrate the unit. The best part is the ability to easily re-calibrate the meter. The process is so simple compared to the cheap units that I find myself calibrating it more often which is a good thing. Other models required the use of three different test solutions to calibrate them and the required steps are about as kludgy as you can imagine. This unit requires one calibration solution and it is recommended to use one that is near the range you'll be measuring for most often. In my case it's the 7.0 solution. It comes with a nice cap that allows the unit to stand on end for storage. It also comes with a small amount of electrode storage solution (which I did not even know you needed until I purchased this one), that you use in the cap to keep the sponge moist which protects the electrode. I have since purchased a larger bottle of the solution from HM Digital so I can store it properly for a long time. I use this meter almost daily and am very pleased to finally have a PH meter I can rely on. It is easily worth the price. If you are reading this it's probably because you have not been able to find a decent PH meter, or maybe it's your first one. Either way, if you need a good accurate PH meter that is easy to use and re-calibrate, don't waste your time and money with the cheap models. Spend the extra money now and save yourself the frustrations I went through. I highly recommend this meter. It's the best you can get in the price range in my opinion and I have the experience to back up this review. Oh and one final note - I think I read somewhere it was made in Korea but assembled in the US where the others were all from China...but I don't know this for sure. It's definitely not a clone like the other cheap models. Update Nov 4, 2021 This is the second of these I have purchased. The first one ended up giving false readings after I left it in some water and nutrient solution for a couple of days by mistake. I suspect it somehow messed up the sensor. I have another tester that is my main one, which I did a review on as well, so I was able to see something was amiss. Since PH is very important to me having more than one unit is a must so you can see if there are problems brewing which did happen to me. Instead of getting a cheaper or more expensive model I decided to get another of these since it served me well for a long time when I was using it as my primary tester. It's not the best tester you can buy, but at this price point it is a very good one and I have no problem recommending it. Just make sure to not leave the probe in water or other solution for an extended period of time. I normally use a solution made to protect the sensor when storing it between uses - which I highly recommend.

I also own the far more precise, and more expensive meter by the same company. It has a replaceable probe that costs almost as much as this entire meter. It was nice to have that precision, of course, but I found that I was rounding off anyway, so I really didn't need it. By that time, i was used to the time it took for that very precise meter to settle into a final reading. When I first began using this meter, it seemed that the meter settled into the final reading almost immediately. Perhaps I've gotten spoiled, or maybe it happens as the meter gets older, but it now seems to take a little longer for the meter to settle in. It still only takes a few seconds, and I rarely wait even a full minute to take a final reading. I calibrate on a regular basis, once every week or two. Sometimes, I find that the meter has barely changed in calibration, and I don't need to do anything. Other times, after longer waits between calibrations, I have found a drift of 0.1 to 0.3, which isn't that much at all for my purposes. Luckily, calibration is simple and easy, and all you need is a source of the calibrating liquid and a small cup. I've abandoned the use of my more precise meter, and instead of buying replacement probes, I just buy another one of these meters every few years. All meters wear out eventually, since it is in the nature of the little glass bulb to slowly erode (which is why you need to recalibrate). In my situation, it makes more sense to get another one of these fine meters with a rapid response time, instead of buying a new probe for the more precise meter with the slower response time. They are all excellent meters, highly reliable, but I have ultimately settled on less precision and a more rapid response.

First off it's really hard for me to like anything because I'm a perfectionist and expect things to be perfect well finally, after buying different PH meters ranging from $6 up to $20 I was never truly happy hey because they all have a small little bitty hole in the back to either calibrate or it's just there on digital models a drop of water in the hole the meter is done as far as ever working properly. I use my meter everyday at least twice a day so I would usually only get about a month out of the other meters they would just constantly have to be recalibrated or would just become worse or get a drop of water in that small hole. All I do know is for the price point I believe that this is the best pH meter that literally feels durable the lid has a rubber seal and when you put it in the fluid within 3 seconds it will give you a baseline pH and before 9 seconds it is telling you exactly what the pH is. The cab has a piece of absorbing cloth so when you put the cap back on if there's any water on the tip it will absorb it and you are supposed to add a few drops of solution on this little foam cloth which keeps your electro lobe nice and clean. I would never leave a long review about a pH meter but I have been so frustrated over the past few years buying these cheap ones that I figured I want at least save a lot of people a big hassle if they like to use theirs more than once a year like everyday or every other day this thing is solid plus it automatically cuts off within like one minute to conserve the battery and they are replaceable. It is also slightly water-resistant which if some water splashes on it it will not hurt the buttons. Well I'm very meticulous and nothing will ever be perfect but this is the best I can find so far for the price range.

The p.h. meter arrived on time. Unfortunately the product did not work correctly. My friend uses this meter and says it works great. I will order another one because I know it's a good product, sometimes things like this can happen. I will update my review when I get a replacement. Hello again. This is an update to my first review above. I returned the first ph tester and recieved a refund within a couple hours of dropping it off at a UPS drop off location. That's fast, and thank you Amazon for being very on top of the game with regards to returns. I ordered a replacement which I received about a week ago. It's supposed to be pre calibrated from the factory to a ph 7. Ph 7 solution is included along with a small packet of storage solution. The tester read a ph of 8.5 in the 7ph solution. No biggie I'll just recalibrate it. I have another accurate tester I use side by side to determine the accuracy of the new HM tester. I use a three point calibration system with three solutions. Ph 7. Ph 4. And Ph 10.01. These are the only ones that can calibrate this tester. So I had to do the calibration procedure 3 seperate times, before it was showing accurate readings, I checked with my other tester (different brand) to confirm accuracy. Mine took 3 times to calibrate in a 3 part solution and a fourth time to confirm accuracy. This pen seems mediocre at best so far, unfortunately it doesn't read to .01 accuracy only to .1 For example if the pen reads 7.0 that means it could be closer to 6.9 or 7.1 which is not accurate enough for my applications. My other pen reads 7.00 then 7.01, 7.02, 7.03 and so on, to 7.10, 7.11, 7.12, 7.13. I have to stay in a range from 6.25 to 6.35 so a ph of 6.28 to 6.30 is perfect for me and also crucial for nutrient uptake. I didn't realize when I bought the pen it was to .1 accuracy NOT .01 or I would have picked up something different. That's my bad for not noticing. So this is fine for pool testing and aquariums but not necessarily for hydroponics. The pen takes at least 30 seconds for the reading to stabilize, usually longer. It has a small display with no backlight. So if your like me and can't see well, this may be an issue. I prefer a larger backlit display with .01 accuracy with readings that stabilize within 5 to ten seconds. I calibrate my other pens at least once a week using three part solutions with distilled water rinse between solutions. Towel wipe, compressed air to blow off any excess moisture. I turn it off between solutions and drying. So calibrate to 7. Turn off. Rinse, dry, turn back on, calibrate to 4. Turn off. Rinse, dry. Turn back on, calibrate to 10.01. Repeat this process until your pen reads all three solutions accurately.

Initially, it seemed fine as a ph meter, a little faster in stable reading, but I did not like that the screen and numbers are a little small for my eyes and had to put it at eye level height to read it and no back lighting nor hold button. 4 months later, it failed, at $36, that's $9/month rent. If you don't mind having to buy one ever few months or 2 per year, then I would buy one of those cheaper yellow ones, they last about the same time and easier for calibration because it uses the common 4.01, 6.86, 9.18 pH buffers. I did have to returned the meter to the manufacture at a shipping cost of $9 because Amazon return deadline had passed and got a replacement with good turn-around time, but it was not calibrated and this meter requires the uncommon 4 pH and 7 pH buffers to calibrate. I requested if they can compensate me for my hassle and expenses but they did not.

I’ve had this meter for 4 years now and even with daily use it’s still dependable. I’ve changed the batteries just twice in that time as well. It’s never off by more than +/-.1 when I calibrate it. And I rarely calibrate. It has never let me down. Always have a healthy crop. Their tds meter with the blue cap has also been right alongside my ph meter for the same amount of time. Same thing with it as well. Always accurate and rarely needs calibrating. The ONLY issue I’ve had with the ph meter is the LR44 batteries I buy usually don’t fit. Not sure if that’s a battery manufacturer issue or the meter itself but that is my only complaint. Worth every cent. I have a $120 combo meter that I gave away because it wasn’t as dependable as the HM pair. Update: 9/8/20- finally had to get a new version of my old PH80. Love it! The new and improved silicone cap holds electrode storage solution forever! Hopefully I can get 4 good years out of this new version.

It worked for a minute. Then, it consistently kept giving random ph readings. I bought calibration solution, the pen would never calibrate properly. The readings became worse every time I tried to use it. Then when I tried to calibrate it, it started giving me an ERR-- MSG. So I decided to open it up. Once opened, I noticed that the batteries inside were corroding producing some type of brown residue. I changed the batteries and tried recallibrating it. Nothing worked. It kept giving bogus readings. This pen is very cheaply made. I will never EVER buy another HMDigital product again. Their PH pen, & their TDS EZ meter are utter garbage. Do yourself a favor and spend more money on something that is highly praised with good reviews, because this thing is junk and a waste of time.

Great ph pen I've used all kinda of cheap ones and was almost about to pull the plug on getting a blue lab but something said go with this one and I'm glad I did it's very accurate just make sure u keep you ph pen storage solution you'll have to buy some and just check the calibration every 2 weeks which it may not need it but just like every pen u want to check it..update it just started to mess up on me I really loved this pen but it want stay calibrated like aa soon as I calibrate 2 hours later its 2 points off and I do everything I'm supposed to I keep it cleaned I bought the storage solution to put in the cap also but its failing