PH Meter, Digital 4 in 1 PH EC TDS Temp Meter for Water Hydroponics, Waterproof DWC PH and EC PPM Water Tester with Backlit for Nutrients Growing, Indoor Garden, Home Brewing, Pool, Aquarium

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.

Seems to work well. During storage the bulb on the end needs to stay moist. I had mildew problems with mine. Otherwise it's ok. Nice it came with a few calibration packets to verify it's operation.

I use this thing all the time I never clean it I forgot to put cap on twice but it keeps on going strong. I've never calibrated it yet but it's accurate because I always double test with meter and ph test solution.

Exactly what I needed for my hydroponics! Worked exactly like it should!

This is a good accurate pen. Just recalibrate it occasionally and it will serve you well. This one was actually calibrated to 7.00 right out of the box, unlike several other brands that have promised that before. I check this one with other pens to verify accuracy and it's right on usually all the time.

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.

More then I thought it would be.

I was in the market for a decent pH/PPM Meter that wouldn't break the bank. A few people recommended this one, and most the reviews I read here were good so I went for it. Shipping was quick and the meter came with good instructions and buffer solution. I was able to calibrate with no issues.The protective cap has a protective sponge that is to be kept moist per the instructions, and you're instructed to add a little pure water to the sponge if it dries. The manual also states water droplets are added during production to maintain moisture of the probe. Since receiving and using the meter, I had no issues with the sponge drying out. I followed all instructions that were provided to, and since I've used a similar meter in the past I was comfortable when using.About 2 weeks after using the meter, I removed the protective cap, only to see the sponge was covered in what looked like white mold. The probe itself was also moldy. I carefully cleaned the probe and cap, but with each use, the problem continued getting worse. I reached out to the email provided in the manual as I was unable to reach out via Amazon. Response was quick, as follows :"We are sorry to hear that the sponge is moldy. As the weather temperature rises, no preservatives are added to the sponges, causing the sponges to become moldy.Please clean the electrode tip with a cotton swab or brush, and use tweezers to pull out the sponge.This is a newly upgraded electrode, even without a sponge, it will not affect the pH reading".I did question removing the sponge, but I was assured it would be OK. I very carefully cleaned the electrode like Lucia told me to. For the time being, it seems to be working just fine, but I'm nervous that it will malfunction. I'll update my review if anything changes.