HM Digital PH-200 Waterproof pH Meter, 0-14.00 pH Range, 0.01 pH Resolution, +/- 0.02 pH Readout Accuracy

FWIW, I'm writing the review from the POV of a spa user. You can use this tester for your pool, salt water aquarium or your hydroponic planter. My supposition is, you're looking at this item because you have needs above and beyond test kits or simple test strips. With this pH meter (potential of hydrogen), you'll be able to quickly tell what your water's pH is. HM also has a total dissolved solid (TDS) meter, the COM-100, which I've had for about a week and absolutely love. The unit is waterproof, light weight, a bit smaller than the size of a small "C" cell flashlight or about the size of a large cigar. It's easy to use, easy to maintain, has a small form factor for storage purposes and once calibrated, I feel it's an accurate piece of test equipment that gives you the feeling of having control over your spa tub water chemistry. The unit comes from the distributor pre-calibrated. Batteries are included. A cautionary warning note, the sensor periodically needs to be replaced. The replacement sensor number is: SP-P2. Replacement is a simple process of remove, replace and calibrate. Delivered, the sensor runs about $45.00. Knowing the pH of your water is an important aspect of monitoring spa water chemistry. Without a pH meter of this kind, one won't have a dependable clue what their pH level is. Using test strips or a test kit, my experience, readings can easily be off by up to 1.1 pH. Having your pH out of whack can cause you to have the condition of your water being too acidic, which can damage your heater element as well as low pH can be hard on eyes and skin. If the water is too base, you'll have to deal with calcification/scaling/cloudy water problems which is hard on the tub, jets and plain yucky to get in. The alternative to this meter, test strips or test kits is having to take the time and regularly drop in to your local pool/spa supply house with water sample in hand, where they're going want you to spend more money. And I hate spending money on chemicals I might not need. This all so I feel good about getting my water tested for free. With this tester, that's no longer an issue. And If you're a bit geeky, enjoy the feel of accurate test data and like the peace of mind created knowing you have control over your water's chemistry, after using this tester a few times, you'll feel confident that you're finally in control of your water's pH reading. Yes, in my opinion, the PH-200 is a bit expensive but if you have the extra green, for the peace of mind and control over your water chemistry this tester gives you, you'll quickly come to the same conclusion I came to; money well spent. Why? Because this tester is da bomb. Note 1. Be sure to buy some calibration solution so you know your reading is accurate due to proper calibration. Calibration is simple. Holding the middle button in for a few seconds puts the unit in calibration mode. Place the meter in the calibration fluid and then fine tune the reading displayed in the LCD using the up/down arrows. In this case, for spa water, I use 7.0 pH calibration fluid. You want to use a calibration fluid that's close to your expected needs: 4.00, 7.00 or 10.00 pH. In the case of this tester, calibration is no more difficult than using a television remote control. Note 2. Amazon has calibration packets for sale and with distilled water from the grocery store, you can mix up your own calibration fluid. FYI, you will need to have something like a 100ml graduated cylinder on hand to accurately measure the amount of distilled water you'll need when you mix up a batch of calibration fluid. Also needed, is some "electrode storage solution" to keep the sensor bulb wet. No big deal to use. Put a half dozen drops of fluid in the protective cap that covers the sensor, place the cap on the tester like a pen and you're good as long as the tester is stored standing upright to keep the fluid inside the cap. This is a very sensitive measuring device. This extra effort is not as big of a deal as I make it out to be. Once you do the first time, you're good. And if you care about decent testing gear, you won't mind this bit of extra effort and you'll be glad you got one of these pH testers. Hope the above helps.

I assume that most of the folks who have broken this quality probe or complained about how fragile it is have never used a quality/accurate PH meter before. The nature of the beast requires that the sensor be made the way this one is, and also that it remain wet with a storage solution at ALL TIMES! There is no gray area here folks! If you fail to rinse the end of the probe off with a spray bottle of distilled water after each use and then store it in the special reservoir cap with the sponge to hold the storage fluid up against the glass/gel sensor, YOU ARE ASKING FOR TROUBLE! The original unit I bought (Not from Amazon) arrived dry as a bone with the storage solution evaporated. I returned it for a refund and purchased the meter from another dealer who took better care of his stock. If your meter arrives dried out, I would suggest doing the same thing. Although the sensor can sometimes be rehydrated, I would be dubious as to the accuracy and prefer to get a replacement that was stored properly and/or didn't sit on a dealer's shelf for an eternity. In terms of the fragility of the glass sensor itself... The sensor end of the probe has a three sided housing that is designed to extend out beyond the actual glass sensor bead and shield it from impact from the sides, but obviously, if you manhandle the thing like a Gorilla and carelessly dunk it into a glass beaker or other container, there is a good chance that you are going to bring the sensor bead straight down onto the rim of the container or something and crack or shatter the sensor! DUH!! This thing is definitely not IDIOT PROOF, so idiots should probably look for something else or have someone with better hand/eye coordination do their testing for them! I purchased my original PH-200 well over two years ago and use it several times a day in my hydroponic garden. NEVER broke a sensor, never had one dry out, never had a problem with calibration, never had a problem with the device in any way! I like this brand and this model so much, I just bought another one here on Amazon because my original is getting close to needing a sensor replacement, and I had a gift card here and figured it would make sense to just buy an entire new unit for now and a new sensor for the original later! The auto calibration is GREAT! Buy yourself some calibration reference solution of 4.0 and 7.0 PH and READ THE INSTRUCTIONS ON THE LABEL ON HOW TO CALIBRATE the device. Unlike other meters in this general price range, there is no calibration screw to turn, no hassles at all! Just hold the CALIBRATE button down while the probe is immersed in the "quality" reference solution of your choice, and wait till the display reads "END". Takes about 5 seconds from start to finish after letting the sensor sit in the reference solution for a FULL MINUTE before hitting the button! DON'T DO WHAT MOST OF THE 1 AND 2 STAR REVIEWERS HERE DID AND CONTAMINATE THE CALIBRATION REFERENCE SOLUTION, AND THEN WHINE ABOUT THE UNIT FAILING TO CALIBRATE PROPERLY! Some lab guys calibrate before every test, and with this model, it is so easy to do, it really can be done in less than 5 seconds by pushing a button and waiting for the probe to self calibrate to the solution it is sitting in. It uses its PH measuring ability to identify the PH of the base solution you are using and calibrate accordingly. (7.0 or 4.0) In terms of accuracy... Like one of the other owners said... This thing is almost as accurate as the $1500.00+ lab grade PH meters, which is definitely saying something! So... Like anything, the device is only as good as the person using it and most of the low review scores are testament to how NOT TO USE THIS DEVICE! If you treat your equipment like crap and don't like reading owners manuals then this probe is probably not for you. If on the other hand, you are looking for an excellent WATER PROOF probe made by a company well respected in the laboratory equipment industry, a model that is considered by those who should know to be one of the best PH probes you can buy, then look no further than the PH-200. And when your unit arrives... READ the manual, and use some COMMON SENSE in handling it and it should give you years of trouble free service! I would give this thing 10 stars if I could, it is that good!

The HM meter costs a bit more than the Hanna machine, but the difference is worth the cost and more. I bought the Hanna machine, but soon I accidentally immersed it beyond the maximum line, and the unit has never recovered. I took it apart and dried it under gentle heat and then soaked the sensor in pH 7.0 solution for days, but no good. It would not calibrate over the 4.0 to 7.0 range repeatedly. The HM meter is waterproof, very sturdy, and measures temperature as well as pH. Its readout goes to two decimals instead of one. The readings may vary within +- 0.02, but not beyond that. It is quite repeatable. Automatic calibration is a snap. If you read the instructions, you cannot fail. Conclusion: It is the most hardy, reliable, and useful of all the meters under $100.

First meter received with dry bulb; solution had evaporated leaving crystals behind. I wrote for a replacement, specifically asking that the meter be checked. Replacement received. However, the cup was dry with crystalline residue and bits of glass, as the bulb was broken. Obviously, my request to ensure that storage solution was protecting the bulb of the replacement, was not followed. I suspect that any notes input on requests for return are not passed on to the individuals who pick and pack. I again wrote for a replacement with a similar note. Either a mistake on my part or one on Amazon's resulted in a credit being issued but no replacement being sent. Once I realized that another unit was not on it's way I placed an order. This unit was received with a very small amount of solution along with crystalline material. Instead of returning this unit as well, in my frustration and need, I decided to take a chance on it being serviceable. I put storage solution in the cup, after cleaning the crystals from it, and let the unit sit the rest of the day and overnight. I'm glad to say that the meter has worked very well for me and is used multiple times per day, five days per week. It is accurate and quick at reading pH levels of 2.9 - 10.9 for me (I have an expensive meter in the lab to verify against). Calibration (4.0, 7.0 & 10.0) is done weekly, though probably not necessary at this frequency. Calibration is very easy and requires only a couple minutes. pH is corrected for temperature; an important feature when reading liquids of varying temperatures as I do. The unit is rinsed in clean tap water and the bulb capped in the solution filled cup immediately after each and every use. It is stored upright for fear that the cup might accidentally leak.

I had a HM Digital PH-200 meter and I thought it was good meter so I bought a second one for another location to measure hydroponic solution. I am working on the third meter and still trying to get one that works consistently. The first one was one from Amazon that was from the "just as good as new program" at half the price. It arrived missing the calibrating solutions, storage solution, and lanyard. The sponge in the end of the cap was missing so it arrived dry and a guess for how long. I soaked it in KCL solution I had for 24 hours and when I tried to turn it on it did not work. Amazon was awesome and refunded me no problem. I ordered the second PH-200 meter, and learned that not everything is sold by Amazon, but the pen #2 came from a third party vendor, so I have to deal with the third party for issues, and return shipment to Amazon they pay the UPS, return to third party I had to pay. Pen #2 arrived and I followed instructions for first time use, and calibration. After calibration I realized the back light of the pen was not working, If I had not had the original PH-200 with a working back light I would not have known this one should have a back light. I read the review where someone was disappointed the PH-200 did not have a back light, his just did not work. So I am sending the second one back. I wish I had kept the second one long enough to compare it to the original one I had. I bought HP-200 number three and followed the first time use and calibration. Now I have two HP-200 ph meters, and the expression a man with two watches never knows what time it is applies to ph meters, because I calibrated both meters, put them side by side in the hydroponic solution I am testing and get two different readings. I could understand off by the +/- 0.02 readout accuracy, but they were off by 0.5. Now I do not know which one is the concern, is the one I already had off or the pen #2 off. I re-calibrate both of them again and the spread got better, but not within the 0.04 read out accuracy if one was + 0.02 and one was -0.02. So to confuse myself more, I bought a Bluelab PH pen, calibrated it, and then compared the two HP-200 and the Bluelab and got three different PH readings. They were not off by read out accuracy but off by 0.2 to 0.4. The Bluelab meter goes to a number and stays there, the two HP-200 meters take a longer time to stabilize. Meter #3 stabilizes faster then the original pen I had, so I am getting a new sensor to maybe fix the original pen spread, but even pen #3 is off the Bluelab pen, so I am not sure if the probe on #3 got dried out and lost accuracy or what. I am thinking pen #3 needs to go back to vendor because the accuracy is so far off after numerous calibrations. If you buy a HM Digital PH-200 check the sponge if it is not wet I would assume the meter is NFG and should be replaced, I am speculating, but it appears that HM Digital sends these meters to vendors and the vendor puts them on the shelf for a long period of time, and the vendor probably does not store them on end so the solution in the cap leaks out during storage, so the chance you get a dried up pen is a concern. I have heard several times about ph pens "if the probe drys it dies". if the back light does not work it needs replaced the HP-200 should have a working back light. I do not need +/- 0.02 readout accuracy, but it would be nice to know if I use one meter it is close to the actual PH reading. I have re-calibrated all of these pens repeatedly to try and get a constant and accurate reading. If I did not have a second PH meter I would not have known that a new out of the box ph meter could be off by 0.4 after several calibrations.

Day one of use........Measured 4.0 right out of the box.....I haven't got my 7.0 solution yet, so I did not check that......This meter is pretty straightforward and easy to use... .....it measures ph and temperatures of liquid solutions automatically........ This one costs a bit more than some of the other handheld ph meters, but so far, I am really liking this meter....... The sponge was bone dry when It arrived, but I quickly hydrated it with the storage solution, purchased separately, and it still seems to be working fine..... This meter has allowed me to diagnose why my tomato plants keep having strange spots after many years of prior success.....If this meter lasts 18 months+, using it twice a week when watering, I will be one happy camper.....and will surely upgrade this one to five stars..... Jan 13 2016 - After 3 weeks of use I had to upgrade this meter to five stars because it works so well and is so accurate and easy to use..... Note: Youtube has plenty of helpful videos demonstrating the use of this handheld ph meter.......

I have been using this unit for approx. a month now and so far I am impressed with this unit. Although I purchased this meter for my own personal use, I also work in a professional lab during the day. I compaired this units results with our $1500 meter in the lab and found that this unit is very close in accuracy. The statements about this unit being hard to calibrate are incorect. Having experience with several kinds of pro ph meters I can say with authority that this unit is as easy as it gets to calibrate. I would guess that the other folks here who had trouble probably had defective units. The calibration process is so simple that a person would be hard pressed to screw it up unless you didn't read the manual at all. One other nice feature of this unit is the two decimal point readout. The other units in this price range that are for sale here only have one decimal point display. example-- 7.XX vs. 7.X This feature will be very helpful to anyone who is considering tight control of the solution you are working with. Remember, for every full point that your ph goes up or down your solution is 10 times more acidic or alkaline. example-- 7 vs. 8 ph. Therefore, with a unit that only reads out to one decimal place, for each number movement your solution is twice as acidic or alkaline example--7.1 vs. 7.2 ph and that isn't even taking into account the margin of inaccuracy in these consumer grade units. The only weakness I have found in this unit is that it has auto shut off and likes to turn itself off while I'm in the middle of a reading. The truth is that it is more of a plus than a minus. Considering that if you forget to turn this thing off, the next time you attempt to use it the batteries will be dead and that would be a much bigger pain in the butt than having to hit the power button once in a while, to say nothing of having to buy a new probe tip prematurely because all probe tips have a useful life based on time of use among other things. The other units in this range may be cheaper but the quality and feature designed into this unit make it worth the extra money.

Does the job and is accurate but you need to maintain it in KCL solution otherwise the probe dries out and you will have to replace the probe. For my application I just need qualitative measurements of my fish tank, it is probably easier just use API test kit or test strips which are less hassle

1.) Ultra fast shipping-------A+ 2.) Great customer service, I had to call Hydrofarm because the sensor was dry when I received it. Their response was that the meter will be fine if kept hydrated after first use.------------------A+ 3.) Calibrating with buffer solution is as easy as pie! The instructions clearly indicate how to do this. Follow them closely!-------A+ 4.) The reading will vary a little while you are taking a measurement, but that is perfectly normal. I use this for brewing, and upon having an exact reading of where our PH is has improved the taste of our beer. There is another reviewer that said commonsense is essential when using this tool, I couldn't agree more!! Keep sensor moist at all times, and store in upright position. Use buffer solutions to calibrate often........simple.

جودة التصنيع ممتازه لكن وصلني وهو لا يعمل وقمت بارجاعه

Ras tout est ok juste faire attention le liquide a couler mais l'éponge encore humide

Good working from 3 months

El HMD PH-200 llegó en perfecto estado, nuevo y bien embalado. Tras usarlo, lo que más me ha gustado es que da la lectura muy rápido y la pantalla se ve perfectamente, incluso con poca luz, lo que facilita mucho el uso. Es cómodo de manejar, parece robusto y al ser impermeable da tranquilidad si lo usas cerca de líquidos. La medición tanto de pH como de temperatura es clara y fácil de interpretar. Como pequeño detalle a tener en cuenta, conviene calibrarlo correctamente antes del primer uso, pero una vez hecho funciona muy bien. En general, muy buena compra si buscas un medidor de pH fiable, rápido y fácil de leer.