--- product_id: 231974651 title: "Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow)" price: "R377" currency: ZAR in_stock: true reviews_count: 13 url: https://www.desertcart.co.za/products/231974651-digital-ph-meter-tester-pen-for-water-pre-calibrated-high store_origin: ZA region: South Africa --- # 0.01 pH accuracy 0-14 pH range Pocket-sized portability Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) **Price:** R377 **Availability:** ✅ In Stock ## Summary > 💧 Master your water’s chemistry anytime, anywhere — because precision is the new power. ## Quick Answers - **What is this?** Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) - **How much does it cost?** R377 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/231974651-digital-ph-meter-tester-pen-for-water-pre-calibrated-high) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Pocket-Sized Power:** Compact, lightweight design fits effortlessly in your pocket for on-the-go testing. - • **All-in-One pH Range:** Measures full 0-14 pH spectrum—perfect for water, pools, aquariums, and hydroponics. - • **Smart Calibration Included:** Comes with calibration powders and easy 3-point calibration for reliable, consistent results. - • **Precision at Your Fingertips:** Ultra-sensitive 0.01 pH resolution for lab-grade accuracy in everyday use. - • **Temperature-Compensated Readings:** Automatic temperature adjustment ensures accurate pH values regardless of water temperature. ## Overview The Ruolan Digital pH Meter Pen delivers lab-accurate 0.01 resolution across the full 0-14 pH range in a sleek, pocket-sized design. Equipped with automatic temperature compensation and easy 3-point calibration using included powders, it’s ideal for hydroponics, aquariums, pools, and household water testing. Lightweight and portable, it empowers professionals and enthusiasts alike to monitor water quality with confidence wherever they go. ## Description Product description PH tester usage related issues When the PH meter is turned on in the air, the value jumps irregularly, which is a normal phenomenon. The value in the air cannot be used as a reference. When measuring the water with the PH meter, it needs to be stirred gently (to remove the bubbles attached to the probe), and it takes a period of stabilization. It is normal for the value to jump up or down during the test. Please do not just insert it and read it immediately. White crystalline salt appears around the electrode of the PH meter, which is a normal phenomenon of the PH electrode, and the electrode can be removed by immersing it in water and cleaning. The PH meter electrode is made of glass, which is fragile. Please do not drop it or touch it with your hands. Do not test the water above 50℃. Do not test the strong acid and alkali, which will cause the electrode glass to burst. Product name: 0.01ph automatic calibration ph pen Test item: water ph value Working environment: 0-80℃, RH<95% Measuring range: 0.00-14.00ph Automatic temperature compensation: 0-80℃ Calibration function: two-point automatic calibration Application scope: water hydroponics, laboratory, pool,industrial water treatment, water purifier How to use Take off the pen cover and clean the electrode with pure water Put the pen probe into the solution, taking care not to exceed the water level Turn on the switch, stir gently, and wait for the reading to stabilize After the reading is stable, read the displayed value After the test, clean the electrode with pure water, dry the water on the pen tip in time, and cover the pen cover back Standard configuration： 1XPH meter 3X calibration powder 1X gift box 1X instruction manual Instructions for use of PH calibration powder Precautions Please note that the PH pen probe is a glass product and is a fragile product. Please do not collide with things. Once the damage is not replaceable, you must protect the probe. After use, use absorbent paper to gently absorb the water on the probe. Pay attention to the calibration sequence (6.86-4-9.18) Calibration powder:pH standard solid substance. It can be used after adding water. Suitable for calibrating any type of ph meter. Each package needs to prepare 250ML of purified water. (Note that the configured water must be purified water or distilled water. Tap water and mineral water cannot be used to configure the calibration solution. The water must be added in the required proportion, otherwise it will affect the accuracy of the calibration and increase the error) The configured calibrators shall be sealed with clean bottles and stored in a cool place away from light. The shelf life of the calibration powder is 2 years, and the shelf life of the calibration solution after configuration is 6 months Matters needing attention PH meter has been calibrated before delivery, the buyer does not need to re-calibrate after receiving the goods! In the following cases, the PH meter must be re-calibrated Has been used for a long time after calibration; Special electrode use Frequently; The measurement accuracy requirements are relatively high. About the battery If the backlight brightness drops significantly or the display value is blurred, the battery should be replaced. When replacing the battery, just pull out the battery compartment and replace it. NoteThe polarity of the battery. Review: Handy little ph meter - So I finally got one of these little digital pens to check my water and honestly it has made me feel like a total scientist in my own kitchen. I used to just stare at the tap and wonder if everything was okay but now I can just dip this in and see the numbers pop up right away 💧 It is basically like having a tiny expert living in your drawer who tells you exactly what is going on with your drinks so you dont have to guess anymore. I was actually suprised by how fast it works because I thought it would take ages to get a reading but it is usually done before I can even finish humming a little tune. It is super light and thin too which is great because it doesn't take up any space at all and I can even take it with me when I go to visit my parents 🏠 You just pop the cap off and stick it in the glass and then boom you have all the info you need right there on the screen. I accidentally left the cap off for a few hours once and I was worried I broke it but I just rinsed it off and it kept on working like a total champ. The best part is that the screen is really bright so I can even use it in the morning when I am still half asleep and havent turned all the lights on yet ☀️ I basically just point and click and it handles all the complicated math for me which is perfect since I am definitely not a fan of doing science experiments before I have had my coffee. It fits right in my pocket too so I can even use it to check the water at the gym or when I am out on a long walk in the park. If you are someone who likes to know exactly what is going on with your hydration then this is basically a little dream come true 🥤 Just make sure you keep the sensor clean or you might get some funny readings that make you tilt your head in confusion. I am honestly thinking about getting one for my friend who has a huge aquarium because it is so much easier than those messy drop kits with all the different colors. It is just a fun little tool that makes my daily life feel a lot more organized and I think you would really enjoy how simple it makes everything feel 🌟 It is basically like a magic wand for your water glass which is pretty cool if you think about it. I am very happy with it and I think it is going to stay right next to my favorite mugs for a very long time. Review: Very satisfied - Works great and not complicated ## Features - 【Pre-Calibrated for Immediate Use】The pH meter is pre-calibrated before shipment and can be used directly out of the box. For best accuracy, readings may vary slightly depending on water conditions and environment. - 【High Accuracy & Wide Measurement Range】Measures pH values from 0 to 14 with high accuracy (±0.01 under standard conditions). Provides stable and reliable readings for daily water testing. - 【Easy Operation】Simply turn on the device, immerse the probe into the solution, gently stir, and wait for the reading to stabilize before recording the result. - 【Compact & Portable Design】Pocket-size design allows easy carrying for testing anytime, anywhere. Suitable for home, travel, and outdoor use. - 【Multi-Purpose Water Testing】Ideal for drinking water, swimming pools, aquariums, hydroponics, RO systems, and other environments requiring pH monitoring. ## Technical Specifications | Specification | Value | |---------------|-------| | Customer Reviews | 3.9 out of 5 stars 11,486 Reviews | ## Images ![Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) - Image 1](https://m.media-amazon.com/images/I/61BUiZjq72L.jpg) ![Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) - Image 2](https://m.media-amazon.com/images/I/71nlnulzyOL.jpg) ![Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) - Image 3](https://m.media-amazon.com/images/I/71nuMxLcmjL.jpg) ![Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) - Image 4](https://m.media-amazon.com/images/I/71ARcb1tWJL.jpg) ![Digital pH Meter Tester Pen for Water, Pre-Calibrated, High Accuracy ±0.01, 0–14 pH Range, Pocket Size for Drinking Water, Pool, Aquarium & Hydroponics (Yellow) - Image 5](https://m.media-amazon.com/images/I/718yHTTwlzL.jpg) ## Available Options This product comes in different **Color, Size, Number Of Items** options. ## Questions & Answers **Q: How do I get warranty support? I have had this for 3 months and it quit working, just shows zero with an occasional flash of random numbers.** A: It's the horrible design in the battery tray. The pressure that keeps the metal contacts down also lifts the entire battery tray away from it's case making it lose contact. You can try to press them back but it will only happen again. **Q: can i get more Calibration powder?** A: Yes, available on Amazon. I use liquid ph 7 which I think is more economical and much simpler to use. **Q: where are the batteries? it says included. are they installed inside? Mine won't turn on** A: Yes they are installed. They are most likely dead, both meters I received came with dead batteries. The thin black cap comes off if the push in the release on the back and pull it up. **Q: Can this be used to test the pH of automotive coolant in your radiator??** A: Yes. It’s a general liquid ph meter ## Customer Reviews ### ⭐⭐⭐⭐⭐ Handy little ph meter *by S***S on December 30, 2025* So I finally got one of these little digital pens to check my water and honestly it has made me feel like a total scientist in my own kitchen. I used to just stare at the tap and wonder if everything was okay but now I can just dip this in and see the numbers pop up right away 💧 It is basically like having a tiny expert living in your drawer who tells you exactly what is going on with your drinks so you dont have to guess anymore. I was actually suprised by how fast it works because I thought it would take ages to get a reading but it is usually done before I can even finish humming a little tune. It is super light and thin too which is great because it doesn't take up any space at all and I can even take it with me when I go to visit my parents 🏠 You just pop the cap off and stick it in the glass and then boom you have all the info you need right there on the screen. I accidentally left the cap off for a few hours once and I was worried I broke it but I just rinsed it off and it kept on working like a total champ. The best part is that the screen is really bright so I can even use it in the morning when I am still half asleep and havent turned all the lights on yet ☀️ I basically just point and click and it handles all the complicated math for me which is perfect since I am definitely not a fan of doing science experiments before I have had my coffee. It fits right in my pocket too so I can even use it to check the water at the gym or when I am out on a long walk in the park. If you are someone who likes to know exactly what is going on with your hydration then this is basically a little dream come true 🥤 Just make sure you keep the sensor clean or you might get some funny readings that make you tilt your head in confusion. I am honestly thinking about getting one for my friend who has a huge aquarium because it is so much easier than those messy drop kits with all the different colors. It is just a fun little tool that makes my daily life feel a lot more organized and I think you would really enjoy how simple it makes everything feel 🌟 It is basically like a magic wand for your water glass which is pretty cool if you think about it. I am very happy with it and I think it is going to stay right next to my favorite mugs for a very long time. ### ⭐⭐⭐⭐⭐ Very satisfied *by S***R on April 30, 2026* Works great and not complicated ### ⭐⭐⭐⭐ Cheap but works *by J***E on December 11, 2025* Works ok for short term use. Loses calibration quickly. Would get 2 or 3 and use them all at the same time for anything sensitive. ## Frequently Bought Together - PH Meter for Water Hydroponics Digital PH Tester Pen 0.01 High Accuracy Pocket Size with 0-14 PH Measurement Range for Household Drinking, Pool and Aquarium - General Hydroponics pH Control Kit For A Balanced Nutrient Solution - FoxFarm Fertilizer Soil Trio Liquid Nutrient: Tiger Bloom, Grow Big, Big Bloom Bottles - (Pack of 3-1 Pint) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.za/products/231974651-digital-ph-meter-tester-pen-for-water-pre-calibrated-high](https://www.desertcart.co.za/products/231974651-digital-ph-meter-tester-pen-for-water-pre-calibrated-high) --- *Product available on Desertcart South Africa* *Store origin: ZA* *Last updated: 2026-06-05*