pH Chlorine Meter Digital Salinity pH Tester for Saltwater Pool Salt Reader for Fish Tank Koi Pond TDS Test Pen All in One pH CL Salt ORP EC TDS Temp Monitor Hydroponic pH Conductivity PPM Tester

When I first used this meter I of course calibrated it. It held the calibration for about a week then the readings went wild...oh no. So, I calibrated it again and it has been consistent ever since. I routinely verify its reading with another (way more expensive) meter and some paper pH test strips and this YINMIK is spot on. I like it especially for the price. It is my 'daily driver'.

Works as expected

This model is a great upgrade from the priors. Calibration was simple and right on target. No more guessing on my reading anymore.

Item was delivered on time. One of the nicest meters I have ever bought. The display screen is very easy to read and very bright. Simple instructions. It even came with extra ph solutions. It seems to be built very solid and the size is perfect. I didn't even calibrate it before first use. I am going to say that it is a quality meter with a low price. Will buy again.

The measurement is quick and accurate. I like this p h pen. The probe has a replacement.You can buy too.

Probe is reading pH's of buffer solutions almost 1.01 whole point lower than each pH packaging implies should be (4.00 solution offers 3.01 reading, 7.00 solution offers 6.01 reading, and the 10.10 offers 9.11 reading). pH of buffer solution was tested w/ pH strips to ensure the solution values were accurate prior to attempting calibration, and of course mixed the powders with 250ml of distilled water as directed. The whole point of calibration is being able to adjust output readings based on input values so that output is setting out the correct measurements. This pH probe is useless as is unless I want to add .99 to each and every measurement I take, though I have no confidence in the product anymore anyway. Also, the cap contained a sponge that instructions indicated was supposed to be moist. It wasn't, and there was some kind of unknown clear slime on the inside of the cap that I'm sure the probe had contact with or that somehow leaked from the probe. Either way, I'm not happy. Product packaging instructions indicated it could be returned or replaced within 12 months, but Amazon's stated option is only 30 days. We're about 15 days past that, so I guess I'm just ripped off. Sometimes it reads straight 0000 across unless you kind of knock it against the glass, insinuating that there is a faulty connection or chip in there somewhere (despite unscrewing and ensuring everything is connected properly). *Editing to add* This product did not come with the calibration solution for EC/TDS settings either, nor the storage solution (I read in a review that product finally calibrated correctly after being submerged in SSolution for 24 hours, and given the cap sponge was so dry, thought I would try BUT I don't even have that option here. Did add a couple of drops of distilled water to cap sponge as per instructions, but it does not seem to matter much) And, only 2 packets each of 4-7-10.01 pH buffer solutions, which is also unhelpful beyond 2 calibrations, IF they had worked in the first place.

This pen is very easy to setup. Comes with batteries ready to go. Comes with packets to balance the pen. You will need some distilled water to help calibrate. I recommend it. So far so good few years in.

Works ok, but not water proof. A little water got into it and it would only read 0's on the PH. After drying it out over night it worked again. I almost returned it.

Followed instructions exactly. Tried 20 times. You’re supposed to turn on unit, place it in 7 ph calibration solution, let it settle and then hold cal button for 5 seconds. That’s supposed to enter calibration mode. Tried holding everywhere from 2 seconds to 30 seconds. No matter what it won’t calibrate making it useless. Unless the seller can fix this I’ll be sending it back. Waste of money and most importantly time.