bluelab pH Pen - ± 0.1 pH Accurate, Durable Double Junction Probe, Waterproof & Floats, Auto Temperature Compensation, Easy Calibration - Made in NZ

2/18/25 Update:BlueLab reached out to me to resolve the issues I was having. They ended up sending me a new pH pen and shared some information on a few things worth considering. My new pen arrived and the storage cap was still moist with storage solution (this is a good thing). The new meter does work better than the original one, but I also suspect that my tap water has "low ionic content" which can cause pH readings to drift (this was also mentioned by BlueLab in their communications with me). I have found that the first readings of the day with the BlueLab pH pen can be a bit low when checking tapwater at my house. If I add nutrients to the water, the pH readings are much more definitive and easy to take. I believe this is to do with the ionic content. I experienced similar behavior with some other, cheaper pH meters. The BlueLab pen reads the calibration solutions quickly and accurately.My advice to anyone new to and/or serious about measuring pH, buy yourself some pH drops (General Hydroponics sells an affordable kit) so you can definitively measure your pH using a visual color matching method and compare to your meter readings. I found that the drops worked the same every single time without error or question or waiting and gave me more confidence in working with electronic pH meters. With some experimenting, I was able to figure out how to get repeatable and accurate readings from the BlueLab pH pen; Sometimes getting a reading of my tapwater that I am confident in takes a few tries. Why get a pen if drops work so well? The color shades when using drops are distinguishable between 6.0 and 6.5 for example, but identifying in between can be difficult to judge. The BlueLab pen gives me 0.1 resolution/accuracy that is needed when doing hydroponic gardening. Having both ways to check pH is ideal.I suspect that pH pens are generally not terribly expensive to manufacture, but it is costly to have a support team available to reach out to communicate with and help customers with their products. Ultimately, BlueLab came through with service, something that is rare these days. I appreciate this and have raised my rating to 5 stars.I really like the BlueLab pen cap, with the sponge that keeps storage solution on the bulb, and the rope used to connect it is also helpful when taking pH samples in a bucket. I do however, wish the the base of the cap was a bit wider so the pen could stand up on its own more reliably. I also wish the meter displayed down to 0.01, not because I need more accuracy, but because I want to see what the current measurement trend is doing (going up/down). The auto off timer also feels a bit short, but I suppose that is both good and bad.1/10/25 (Original Review) I really wanted to like this expensive PH meter. Sadly It came with a dry probe so I soaked it as directed for 24 hours. Calibrated it 3x with Bluelab 4 and 7 solution but readings would drift for several minutes after each calibration. Tap water would measure at 6.4 right after calibration but leaving the pen in the same sample of tap water the reading would drift up to 7.5 after several minutes. It would never read the same value twice. Just a few minutes after calibration it would read the calibration solution several tenths lower than it should. I bought this expecting accuracy, not games. Returning.

These are quality. I get a new one every yr or so. They should be good for around 18 months I read. For $100 the peace of mind it brings is priceless. Gardening can be hard enough so this in conjunction w the EC meter make it quick n easy.I wish the backlight stayed on longer and it takes it a minute to settle in and give u an accurate reading. My only 2 complaints.

This item is amazing! I use it primarily for home pickling needs

I've used a lot of ph readers over the years and Bluelab's is the most thoughtful. The storage cap is well designed to keep the bulb hydrated and the lanyard attached to the cap is the perfect length. The little ring at the top is a nice touch too, makes it easy to hold and use.

Seriously save your money. I keep seeing this pen routinely recommended for some reason as it was to me and decided to write a review to at least save some people some money. Stop buying this overpriced pen!! Its insane what this costs now. I admit I am bitter about it as I truly feel I got ripped off.I run two hydroponics gardens and two aquascaping fish tanks, both with pH sensitive shrimp species. I also run C02 to the fish tanks to help grow the plants, which lowers pH throughout the day. In fact, one of the ways to tell what your C02 concentration is by the relationship between pH of the water and KH (another test), but my point is simply that pH is important to me, and I am just mentioning it to prove I know a thing about water chemistry to say the least.This Bluelab pen is slow to respond at best, but totally way off at worse. Even after calibration it just can't be relied upon to give me accurate numbers. I use a cheapo pH meters and those give me consistent and accurate results. You can buy 5 of those and get better results than this pen gives! Better yet, at least on the aquariums I also use a basic API pH test kit, (where the water color changes based on PH) and again side by side the accuracy of that is hands down better than this pen.Is it possible I just got a bad pen? Maybe. I am aware of the "rules" on the pen - do not let it dry out, store the bulb in the proper solution, rinse it well before using, and pro tip - make sure to tap it so any air bubbles in the bulb float up and do not impact results. But even through all that, it calibrates fine, leads me to believe it will work and then goes wildly off. It cant be trusted. I do not like to write bad reviews but between the cost and my experience I am just hoping to help others. Go buy the $15 ones.

I have been using these for over 10 years so I know how to use it. It’s just stuck at 7.0 no matter what. Calibrated 2 times. Nothing. The one I bought over an year ago also stopped working so now I have just purchased a third one so I can return it and if this one doesn’t work, I’ll never use blue lab again unfortunately! Update. Blu lab returned my money. They still have me as a customer.