--- product_id: 257063446 title: "HM DIGITAL DM-2 Commercial In-Line Dual TDS Monitor Meter Testing For Hydroponics Gardening Aquariums Reefs Pools Spas Water Treatment Drinking Pure Filter system" brand: "hm digital" price: "VT16722" currency: VUV in_stock: true reviews_count: 5 category: "Hm Digital" url: https://www.desertcart.vu/products/257063446-hm-digital-dm-2-commercial-in-line-dual-tds-monitor store_origin: VU region: Vanuatu --- # Real-time dual TDS monitoring Battery-powered portability Advanced dual microprocessor tech HM DIGITAL DM-2 Commercial In-Line Dual TDS Monitor Meter Testing For Hydroponics Gardening Aquariums Reefs Pools Spas Water Treatment Drinking Pure Filter system **Brand:** hm digital **Price:** VT16722 **Availability:** ✅ In Stock ## Summary > 💧 Stay ahead with precision water insights — because pure water means pure performance! ## Quick Answers - **What is this?** HM DIGITAL DM-2 Commercial In-Line Dual TDS Monitor Meter Testing For Hydroponics Gardening Aquariums Reefs Pools Spas Water Treatment Drinking Pure Filter system by hm digital - **How much does it cost?** VT16722 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.vu](https://www.desertcart.vu/products/257063446-hm-digital-dm-2-commercial-in-line-dual-tds-monitor) ## Best For - hm digital enthusiasts ## Why This Product - Trusted hm digital brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Crystal Clear Display:** 3.1-inch high-res screen (1920x1080) ensures instant, easy-to-read water quality data at a glance. - • **Battery Included & Ready:** Comes with 2 AA batteries for immediate use—no downtime, no hassle. - • **Plug-and-Play Installation:** Easy in-line setup integrates seamlessly into existing water treatment and filtration systems. - • **Industrial-Grade Durability:** Built to withstand demanding environments like car washes, manufacturing, and food processing facilities. - • **Precision Dual TDS Monitoring:** Simultaneously track feed and product water quality with in/out electrode probes for unmatched accuracy. ## Overview The HM DIGITAL DM-2 is a commercial-grade in-line dual TDS monitor featuring advanced microprocessor technology for precise measurement of total dissolved solids in feed and product water. Designed for industrial applications such as hydroponics, aquariums, pools, and water treatment, it offers a high-resolution 3.1-inch display and easy installation. Battery-powered and compact, it delivers reliable, real-time water quality monitoring to optimize your system’s performance. ## Description Commercial In-Line Dual TDS Monitor DM-2 with Advanced Microprocessors. Commercial In-Line Dual TDS Monitor DM-2 with Advanced Microprocessors. Review: Well built and water proof Review: This TDS meter works great with water filtration systems where you want to regularly monitor the water quality. Installation starts with the mounting bracket which can either be stuck on with double-sided tape or screwed onto a cabinet door like I did. The meter easily slides in and out of the bracket which is necessary for future battery changes. Connection to the RO system is simple - the red line (labelled IN) goes between the cold-water source and the RO filter's input line, while the blue line (OUT) goes between the RO's output line and the RO's faucet. All connections use quick-connects which means no extra hardware needed - just push the tubes into the tees. The manual warns about not pushing too far in which can damage the sensor, so measure and mark the tubes before inserting them. Using the meter is also straightforward; press the power button, a light comes indicating which line it's reading, then a continuously updated reading appears on the LCD display. Pressing either IN or OUT buttons gives readings for that line. The meter remembers which line was last chosen, which is handy because I mostly keep an eye on the quality of my filtered water. The meter automatically shuts off in a few minutes to save on batteries. The dual meters are far more convenient than individually reading samples of tap water and then filtered water with a handheld. This meter is pre-calibrated, but I confirmed its accuracy with a handheld. I installed this alongside a new Watts five-stage RO system and I'm glad it did - it helped me find out that the membrane was defective new out of the box! At first, my unfiltered water averaged between 160-180PPM while filtered water came out around 60-80 - at 66% filtration, that's far below the advertised 92%+. After a membrane replacement under warranty, it now reads around around 3-8PPM which is the same as what the local bottled water store sells. The biggest gripe with this meter is the lack of a battery door - especially where there's room for one. Instead, 4x screws need to be removed to get to the batteries. On that note, it's nice that it uses 2x AA batteries which should be both easy to find around the house and last longer than mini-button cells. A lesser design issue is the bad choice of location for the line IN/OUT LED lights - they're bright and so close to the LCD display, it's distracting - they should have put the LED's behind the display to make it backlit and readable in the evening. Overall, this a must-have for water filtration systems if you want to take the guesswork out of replacing RO membranes and filters. I paid slightly less than the price of two handhelds, but the dual meters in this monitor makes it a convenience that's worth spending the extra money on. ## Features - The Dm-2 Tds Meter Installs On Industrial Systems Such As Car Washes, Window Washing, Manufacturing, And Food Processing - The Commercial In-Line Dual Monitor Is Highly Efficient And Accurate Due To Its Advanced Microprocessor Technology - This Dual Monitor Displays Total Dissolved Solids Levels Of The Feed Water And Product Water With In And Out Electrode Probes - Brand Name: Hm Digital ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000VVYRVQ | | Additional Features | Industrial Applications, Advanced Microprocessor Technology, Auto-Off Function, Water-Resistant Casing, Extra Large LCD Display, Longer Waterproof Shielded Cables, Variable Mounting Bracket, Quick-Connect T-Fittings | | Aspect Ratio | 16:9 | | Brand | HM Digital | | Brightness | Appropriate for clear visibility | | Color | White | | Compatible Devices | DM2, DM-2, DM-2-2550, HMDM-2 | | Connectivity Technology | HDMI, DisplayPort, DVI, VGA, USB | | Contrast Ratio | 2000:1 | | Customer Reviews | 4.3 4.3 out of 5 stars (109) | | Display Resolution Maximum | 1920 x 1080 | | Display Technology | LCD | | Display Type | LCD | | Global Trade Identification Number | 00826333000100 | | Hardware Connectivity | Unknown | | Has Color Screen | No | | Item Weight | 0.5 Pounds | | Manufacturer | HM Digital | | Model Name | DM-2 | | Model Number | DM-2 | | Mounting Type | VESA No | | Native Resolution | 1920x1080 | | Power Consumption | 3 Watts | | Refresh Rate | 60 Hz | | Resolution | FHD 1080p | | Screen Finish | Glossy | | Screen Size | 3.1 Inches | | Series Number | 1 | | Shape | Rectangular | | Specific Uses For Product | Commercial | | UPC | 886566017467 826333000100 797267347473 886566120525 799705707115 603964473547 609132242342 701003119576 | | Unit Count | 1.0 Count | | Viewing Angle | 170 Degrees | ## Product Details - **Aspect ratio:** 16:9 - **Brand:** HM Digital - **Resolution:** FHD 1080p - **Screen size:** 3.1 Inches - **Screen surface description:** Glossy ## Images ![HM DIGITAL DM-2 Commercial In-Line Dual TDS Monitor Meter Testing For Hydroponics Gardening Aquariums Reefs Pools Spas Water Treatment Drinking Pure Filter system - Image 1](https://m.media-amazon.com/images/I/71p9etz0vAL.jpg) ## Questions & Answers **Q: Why does the description not show the size lines for in and out this unit will fit?** A: Fittings Size (1/4" TEE fittings)In case you need a bigger size fitting 3/8" for example we carry it ,you can search the following item B00TG08TQM H2o4u **Q: What t fittings do I need to put this inline of my 3/4” pex? I’m assuming a few different fittings.** A: I am sort of going from memory, but I bought the white, I think teflon, fittings that are readily available at big box stores like Home Depot and Lowes. I believe the fitting provided is 1/4" so you need a pex fitting that fits the size of you pex pipe, but the "T" piece needs a 1/4" to take the one provided. I don't remember any particular difficulties, but in fact I was attaching to 3/8 white plastic tubing, so I needed a different "T" piece from the one you require. Its all a matter of finding the right "T" piece. I took a quick look, and the pex fittings are all compression fittings, so you might have to put a plastic loop with a t piece in the middle to take this device. Lots of ways to skin a cat. **Q: How long are the cables? And is it for 1/4" ID RO line? Your missing the basics in the description** A: On the unit I purchased, the cables are approximately 45" long. It includes two "T" fittings for 1/4" RO/DI lines. **Q: is this available with 1/2'' x 1/2'' x 1/4'' tee fitting? i need the probes to go to 1/2'' tubing** A: You can purchase 1/2 x 1/2 x 1/4 push-in fitting tees to replace the ones that come with it. I'm doing the same thing with a DI system for my detailing business. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Review *by T***V on 7 April 2025* Well built and water proof ### ⭐⭐⭐⭐⭐ Review *by T***. on 16 April 2016* This TDS meter works great with water filtration systems where you want to regularly monitor the water quality. Installation starts with the mounting bracket which can either be stuck on with double-sided tape or screwed onto a cabinet door like I did. The meter easily slides in and out of the bracket which is necessary for future battery changes. Connection to the RO system is simple - the red line (labelled IN) goes between the cold-water source and the RO filter's input line, while the blue line (OUT) goes between the RO's output line and the RO's faucet. All connections use quick-connects which means no extra hardware needed - just push the tubes into the tees. The manual warns about not pushing too far in which can damage the sensor, so measure and mark the tubes before inserting them. Using the meter is also straightforward; press the power button, a light comes indicating which line it's reading, then a continuously updated reading appears on the LCD display. Pressing either IN or OUT buttons gives readings for that line. The meter remembers which line was last chosen, which is handy because I mostly keep an eye on the quality of my filtered water. The meter automatically shuts off in a few minutes to save on batteries. The dual meters are far more convenient than individually reading samples of tap water and then filtered water with a handheld. This meter is pre-calibrated, but I confirmed its accuracy with a handheld. I installed this alongside a new Watts five-stage RO system and I'm glad it did - it helped me find out that the membrane was defective new out of the box! At first, my unfiltered water averaged between 160-180PPM while filtered water came out around 60-80 - at 66% filtration, that's far below the advertised 92%+. After a membrane replacement under warranty, it now reads around around 3-8PPM which is the same as what the local bottled water store sells. The biggest gripe with this meter is the lack of a battery door - especially where there's room for one. Instead, 4x screws need to be removed to get to the batteries. On that note, it's nice that it uses 2x AA batteries which should be both easy to find around the house and last longer than mini-button cells. A lesser design issue is the bad choice of location for the line IN/OUT LED lights - they're bright and so close to the LCD display, it's distracting - they should have put the LED's behind the display to make it backlit and readable in the evening. Overall, this a must-have for water filtration systems if you want to take the guesswork out of replacing RO membranes and filters. I paid slightly less than the price of two handhelds, but the dual meters in this monitor makes it a convenience that's worth spending the extra money on. ### ⭐ Review *by L***P on 17 March 2021* J'avais acheter HM Digital Dual TDS Mètre pour contrôler la conductivité de l'eau à l'entrée et la sortie de mon osmoseur je me suis aperçu que les 2 sonde n'indiquer pas la bonne valeur .j'ai acheter une soluiton d'etalonage comme precisé (TDS 342 PPM HM DIGITAL) sonde 1=459ppm et sonde 2=448. en voulant recalibre mon appareille et en suivante les instruction [ Si la lecture sur le moniteur (pour l'une ou l'autre ligne) ne correspond pas à la solution, ajustez la lecture vers le haut ou vers le bas en tournant doucement les équipages en plastique orange à l'arrière de l'appareil dans le sens des aiguilles d'une montre ou dans le sens inverse des aiguilles d'une montre pour augmenter ou réduire la lecture.] je me suis aperçu qu'il n'y a pas les vis de réglages.Ducoup l'appareille ne me sers a rien si je ne peux pas l’étalonner ,j'espere que se commentaire permetra a d'autre personne de ne pas se faire avoir. ## Frequently Bought Together - Commercial In-Line Dual TDS Monitor - HM Digital TDS-3 Handheld TDS Meter With Carrying Case, 0 - 9990 ppm TDS Measurement Range, 1 ppm Resolution, +/- 2% Readout Accuracy - HM Digital C342 TDS and EC Calibration Solution, 342 ppm (NaCl), 90 ml Volume, Transparent/Blue --- ## 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.vu/products/257063446-hm-digital-dm-2-commercial-in-line-dual-tds-monitor](https://www.desertcart.vu/products/257063446-hm-digital-dm-2-commercial-in-line-dual-tds-monitor) --- *Product available on Desertcart Vanuatu* *Store origin: VU* *Last updated: 2026-05-16*