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

Seems to work justr fine, may ber it should be calibrated before first use.

Once i plugged it together it will not come apart and pulling harder to try and get it apart only makes it's reading go crazy don't buy this.

The app doesn't work.

Use very often!

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.

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

I got this meter to read the dissolved oxygen levels in my many fish tanks. They are all planted and should not have any issues with oxygen, but I had one tank that could not support even a few shrimp. After all of the basic parameters checked out I decided I should find a way to determine the amount of the oxygen in the tank. Reduced oxygen could indicate a chemical issue with the tank or a bacterial infection, or insufficient filtration, among other things. This meter comes with well-written and easily-understood directions. There are a few grammatical issues, but the manual was presumably written by someone who doesn't speak english as a first language, and considering this, it's well done indeed. If you follow the instructions laid out in the book the meter works exactly as intended. It is crucial that you perform both the zero and slope calibrations prior to using the device or the obtained readings will be meaningless. I found the meter to be accurate, especially when using the conversion chart for temperature that's in the book. When used qualitatively you can see if there are glaring issues with the oxygen levels in your tanks. I'm not using it to split hairs, a percent difference here and there isn't what I'm concerned about, so now that I trust the device I'll only be using the correction factors to spot check the meter. The probe has to be filled with electrolyte to work and is sensitive to damage and drying out, so this meter requires maintenance that standard pH and salinity meters don't. It comes with spare probes and spare electrolyte so when the probes ultimately are consumed you have plenty of spares to keep it going. You can also order replacements when needed. All in all this meter does what I want it to do and is relatively simple to use and maintain. If you have a need to measure the dissolved oxygen in an aquatic sample, this meter represents good value.

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.