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, 2021This 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.

For the price, I feel this pen may be the best budget priced option on the market. Works well. Dont forget to calibrate at least 1x a month.

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 .1For 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.

Great product. I like HM. Their solutions and buffers are good.Knew it wasn’t the best for RO or DI water. Rating 3 stars because it underperforms in accuracy and time to landing reading.Even using various lab methods to help with this issue, it’s still just not great for highly purified water when fertilizers are added or liquid nutrients or what have you.It really just underperforms in testing ultra pure water systems with nutrients. But it IS a point calibration meter with the option of a 4,7,10 standard calibration buffer.

Works beautifully. Clear instructions. I owned this model for many years. It finally gave out and I purchased a cheap knock off brand. Needless to say it was a piece of junk. I returned it and bought the HM80 once again. It has proven itself many times over. Don't waste your money on anything else.

after a month requires constant calibration and before anyone ask im using there ph calibration solution and storage solution and before switching from one solution it is rinsed a dried until it flat lines before going into the other