Digital Dissolved Oxygen Meter, GIDIGI Dissolved Oxygen Tester with ATC, DO Meter with 9.84ft DO Probe Cable, Dissolved Oxygen Test Kit for Aquarium, Ponds, Fish Tank Range 0.0‑40.0 Mg/L

Use very often!

The app doesn't work.

Funciona bien, solo hay que calibrarlo la primera vez y ya se puede usar sin problemas

I ordered 8 of these dissolved oxygen meters to use in my classroom. One arrived broken and another stopped working after one week of use. I have not been able to get a refund or replacement from the seller in spite of the claim that they come with a one year warranty.

Edit: Seller reached out to me direct and provided an instruction manual and answered some questions. Will not connect to Bluetooth on Samsung Galaxy S24. No instructions other than "Connect to our app!" No calibration instructions, just garbage pictures on the store listing that leave you to guess what exactly is supposed to happen. Temperature probe reading is ~2°F higher than other probes. I haven't decided if I'm going to return it yet or not... I'm going to try more research and troubleshooting before I give up on it...but so far, I'm not impressed.

Seems to work fine after calibrations. Calibrations are described in the supplied manual, but also in amazon videos. The calibrations are a little painful, but need to be done for every similar instrument. I compared this unit with other companies' products. This one has the advantage to provide quite a lot of measurement capabilities in one unit ("6-in-1") that others break out into several instruments. I am using in for hydroponics. The unit appears to be sturdy. So far so good!

For what it costs, this is a solid little tool and I’m glad I bought it. I mainly use it to check the pH levels and the ORP in my pool - I haven't used any of the other functions. When I compare with my liquid-drop testing it's not pinpoint-perfect, it’s accurate enough to get the job done. It also includes a few extra features that could come in handy if I ever want to test pool water or other things, which is a nice bonus. Though it wasn't a big deal, I didn't enjoy calibrating the device, it wasn't a big deal, but just one more step if you want it to be accurate. My box was missing one of the chemical envelopes to help calibrate the device. The price feels reasonable, and the display is clear and easy to read. Results come up fast, and overall it’s a reliable device. Good if you're in a hurry and don't have time to do the drop test on the pool - it will get you "in the ball park."

Versatile and reliable tool designed for anyone who needs accurate water quality measurements. With its 6-in-1 functionality, it combines multiple testing capabilities—pH, PPM (TDS), EC, salinity, temperature, and ORP—into one compact device, making it an excellent choice for aquariums, hydroponics, pools, spas, brewing, and drinking water monitoring. The meter has a modern, handheld design that is lightweight and easy to use. The LCD screen is bright and clear, displaying multiple readings simultaneously for quick analysis. The body feels sturdy enough for both home and professional use, and the included ORP 222mV calibration solution is a thoughtful addition for maintaining accuracy over time. Accuracy is where this device truly shines. With its advanced sensors and simple calibration process, it provides highly reliable readings across all six parameters. The fast response time makes it especially useful for daily testing routines, whether you’re balancing pool chemicals, monitoring a hydroponic system, or ensuring safe aquarium conditions. This tester is designed with user convenience in mind. The one-button operation and straightforward calibration steps make it accessible even for beginners. Switching between measurement modes is seamless, and the waterproof probe ensures it can withstand repeated use in wet environments without issue. Few testers offer this level of versatility in a single device. It’s particularly useful for users who manage multiple water systems, such as hydroponics enthusiasts who also maintain aquariums or home brewers who need to monitor pH and TDS levels precisely. Its multifunctionality eliminates the need for multiple separate tools, saving both cost and storage space.