Apera Instruments PH60F Premium pH Pocket Tester, Replaceable Flat Electrode for fabric/paper/skin pH Testing, ±0.01 pH Accuracy, -2.00-16.00 pH Range, ±0.5°C Temperature Sensor

I use a ph meter for plant nutrient solution. Previously, I had a couple of cheap China imports, which seemed reasonably accurate for a while, but don't last long. All ph probes degrade over time, so rather than keep buying cheap, I decided to get a more reliable one with a replaceable probe. This is quite expensive compared to some other brands with good reviews, say the Essentials PH Meter, and @ £29 the replacement probe is not much cheaper than buying a new Essentials meter. However, replacing just the probe reduces waste, and gives you options: there are 4 compatible probe types (all available on Amazon), which you can buy separately as replacements, or to measure different substances. The glass bulb is for liquids, the spear probe for solids, such as foods, soil, the flat probe for paper, cloth, skin etc. And you can buy an ORP (Oxygen Reduction Potential) probe to use with this meter, which tells you the "killing power" of your solution/water (sterilising or not, a simplification of complex subject). The life of the probe will depend on how often you use it, and how you treat it. The probe is supposed to last 12 - 24 months - it's CE rated for 6 months (for safe use), but that's NOT its life expectancy. It CAN be stored dry, without degrading it, according to instructions, but storing it dry will affect its sensitivity. So if you store it dry, for accuracy, you need to soak it in the provided solution before use. It can be stored in the soaking solution, but NOT in purified water. The kit comes with everything you need: soaking solution, 2 calibration solutions, batteries, lanyard (quite a long one), 2 containers for calibration, instruction manuals in English and German, as well as a laminated quick reference chart, all in a hard plastic case. The instructions are clear, easy to understand, and contain all relevant info. Instructions say not to use soaking/storage solutions from other companies, but as long as the same (potassium chloride or kcl @ 3 molar strength) and/or for the same type of ph meter, I don't see why. Will be ignoring that myself (no Apera replacements on Amazon, either). The calibration solutions will last quite a while, the soaking solution is enough to fill the cap to the mark about twice. 2 reviews for the replacement probe said the glass bulb was too exposed and breaks easily. I disagree - the bulb is inside and above the plastic rim, which does have gaps in the side, but doubt it would break if dropped on flat surface. IP67 means it's dust proof, and can be immersed in up to 1 m of water, or for up to 30 mins, depending on info source. It doesn't mean it's hermetically sealed, though. Overall, the meter seems robust, and looks like it will stand up well to any normal use. So far, would recommend, despite quite high price, as seems well worth it, all things considered.Edit:Have been using this for 6 years now, about once per week, and it still works fine. Have not calibrated it in a while, but it seems to be accurate enough for my purposes (fertiliser/irrigation solution for plants). Like the back-light feature, and it's very easy to calibrate. If it keeps switching to settings screen when you turn it on, it means batteries need replacing, the battery icon does not seem to show accurately. Have so far replaced mine once.

Very good built quality, simple to calibrate. I love the case with other bits.

Fantastic, exactly what I need for the hot tub. Sick of the stupid cheap ones that are dead hard to calibrate. This one is a breeze to calibrate, very happy with this product.

The best around for the money.I deducted a star because my example was delivered missing a sealing ring, Amazon have sent a replacement by return. After years of using cheap ones for my aquarium, and eventually loosing a batch of fish due to inaccurate readings. I have bought this , and it just performs, easily calibrated, excellent online how to videos. Upgrade your ph meter you won't regret it.

love this piece of equipment. precise as well although replacement liquids are expensive due to shipping.

Really good product, 1st one arrived broken but they sent me another straight out without even wanting the broken one back. So I could just replace the sensor and have two!

This meter just wouldn't hold stable reading or calibrate not sure if I just got a meter with a faulty probe the meter itself and box presented in seemed very well built but it just wouldn't hold a stable reading to calibrate any slight movent and the meter would jump wildly up and down the PH scale. I've found the essentials meters to be the best on budget price at £45 but the Bluelab meter which is priced at £220 and comes in a carry case to be the best PH meter I've used for stability and longevity and in the long run it's best to invest in this meter rather than spending £50 or £40 on replacement meters or probes every 8 to 12 months. I purchased this meter as a back up to my bluelab meter but have now just purchased my second blue lab meter in carry case at £220 as I use two individdual meters in my homebrew to ensure exact readings just in case one should fail. Replacement probes for the Bluelab box meter are priced at £60-70 but they last for two years or more if you look after them.

Easy to set up and use