Apera InstrumentsLLC-AI221 SX610 Waterproof pH Pen Tester, ±0.1 pH Accuracy, 0-14.0 pH Range, Suitable for Test Tube Testing, Replaceable Probe

Have owned other pH Meters. This is highly accurate and easy to use. I highly recommend it, especially those that are new to using a pH meter.

Works flawlessly. For the first several weeks I double checked every reading with ph strips and a blue labs meter, and it was always spot on.I do recommend getting some extra 7ph calibration liquid. You can get larger bottles of it for around $10 usd.I really like that the probe itself is easily replaced. I bought an extra one after a few weeks of use, just because I knew this was going to be my go-to ph tester from now on and I like to have a backup probe just in case. I haven’t needed it and probably won’t for a while, but for less than $25 usd, it’s worth having an extra probe.I also really like that the manufacturer includes a total of four batteries. That’s just a nice little touch that tells me they actually care about their product, and not just their bottom line. They didn’t have to do that- they’d sell just as many without extra batteries. But they’re not common like AAA.. So having extras is very nice! (They’re also not rare batteries, you can get them at most box stores.. Usually sold as key fob batteries).Very pleased with this purchase.

I was very excited to receive my meter today, however, within minutes it became apparent that something was quite wrong. The buffering solution, to begin with, had leaked all over the box. Without testing the meter, I contacted Amazon, whose representative was very helpful. I was offered a partial refund for the buffering solution, and accepted it, figuring that the meter was probably not damaged. Well, I figured wrong: The buffering solution, as it turned out, had clearly already been opened. There was a bit still left in the vial, so I tried to test the meter. The reading, after following the correct procedure, was all over the place, finally settling on a ph of zero (which is pretty weird). Although I couldn’t get a correct calibration, I thought I’d try out a solution of hydrochorous acid I’d made. I had processed it to 200 ppm, and figured roughly, based on ph test strips that it had a ph between 5 and 7. Well, the meter was all over the place. When held still it jumped from 0, stayed on about 7.8 for a second, and then jumped all over the place again. It never properly calibrated, of course, but it seems like it shouldn’t jump all over the place…and finally land on zero again and stay there. So it’s going back.With all of this said, I would have thought that the issue was due to inadequate packaging (it was in a box with one little air pillow thingie and allowed to bang around). However, given that the buffering solution had already been opened and the meter was so wild, I suspect that I was sent a meter that someone else already judged to be defective. Either way, somebody fell down on the job. I am still going to try a replacement in the hope that this one was merely a dud and the unit does get good reviews.

The ph pen I ordered was acting a little wacky so I reordered another one And they had it to my door the next day early too! I was pleasantly surprised if you use ph pens or meters you know you need it when you need it! So I appreciate the next day delivery because I needed it fast and apera is the best brand I wouldn't trust any other pen besides of course blu lab an a few others but price wise this is it comes with everything you need would give 5 stars but it doesn't have a backlight which is very useful not a deal breaker!

So as far as im concerned this ph pen is reliable and i have had no problems. Came with the case, 7.0 calibration fluid and storage solution. First got the pen, the ph was off .1, i did the quick and easy calibration test and have had no problems. Have used it a handful of times and even checked the calibration before each use to be sure and its been on point each time. Definitely recommend if your looking for something above the quality of those $15 ph pens. Just try it, you wont be disappointed or at least i wasn't.Update: Product is working great, i check the ph just to be sure but the past 5 times ive used it it has been on point. Huge difference between a $15 ph pen and this one. I was searching for a product like this for awhile and read all types of reviews, i usually go to the bad ones to see what exactly people are having problems with, i have not expierenced any of what the negative reviews talked about. If you are doing the same thing i was and looking at 10 different ph pens, look no further, i promise this one is worth the money.

Im using this for multiple aquariums. Received it yesterday, picked up some distilled water today to rinse the probe and popped open the storage box containing the pen. Note the package I ordered contained the pen, storage solution, calibration solution, and extra batteries. Which, Im glad I realized they were extra batteries before I tried to open the pen to install them, Im still not sure how to open the pen. But Im glad to know the batteries and probe are replaceable.Out of the box my first impression was that this pen is pretty well made. Im not familiar with lab or medical equipment, but as far as gadgets and tools go this seems of good quality. The instructions were simple and clear enough. With in a few minutes I was calibrated and testing various samples of water, and testing the pen again for calibration. I shut the pen off for a bit made a few adjustments and went back and tested my sample waters again and the pen did hold its calibration. Several hours later, when testing caibration again I found it went up a 1/10 th.At this point Im happy with my purchase and I'll be continuing to use this pen possibly several times a week...