Gain Express 3-in-1 ORP PH Temperature Combo Meter Tester, Pen Type ATC -1999~1999mV 0.00-14.00pH 0~50°C, Water Quality Aquarium, Tank, Swimming Pool, Lab, Spa

I am still debating between keeping the testers just for the ORP reader which was easy to setup and this far is accurate. The was able to calibrate properly once. Then I tested my two aquariums. I first did a chemical test on both by liquid and ProScan strip. The big tank has a PH of 6.5 and this reader returned 7.28 My other tank is at 6.5 as well and the rider gave me 8.1 I tried re-calibrating and I failed three times so I gave up on the PH part

I wanted to know facts about local TAP water, and as well on high price bottled water. The meter worked flawlessly and provided good readings. I also calibrated meter as per know PH of various waters and values from sample water worked as expected. Tap water was always around 7.5 Ph.A good handy tool, nice box for securing and the display are readable although I wished it was a bit bigger. But it's NO burden to read in a regular home or sunlight.The ORP readings were always positive as may be water I tested had no - ions in it. But I do wish to find something to test that shows a negative value.Its good purchase and I am happy so far.

This almost nifty little device does give good temp. and pH readings and includes calibration fluids for pH, but there is nothing to calibrate the ORP meter. The description implies that all calibration fluids are included. Unless you already have a known good ORP meter, (why would you be buying this one?) this is just another pH/temp. meter.

Easy instructions to use the calibration liquid solutions, batteries included, easy to use. Calibration of the pH values was dead on with the 3 solution values. We checked it against an ionizer we have and it was dead on to that. The ORP doesn't have a calibration solution included but we already knew what our ionizer produces and itnwas dead on with that. No need to use the little enclosed screw driver. Perfect.

This is the slowest most indecisive meter I have ever seen. After 2 weeks, it stopped measuring anything but temperature and in CelsiusThe pH reading is a full point off from my other meter and it takes a couple minutes to read. It give or gave a orp but I’m not sure I trust it. The number would keep changing and never settle on a value

Great product with good price, I am very happy to find this meter for my aquariums. Just as what's written in the description, it is very easy to calibrate and provides accurate readings. This has been so helpful in testing my aquariums every week, making sure every temperature check goes smoothly.

The media could not be loaded.  I bought this one because there were more Pros than cons. And for price. I just didn’t expect it to be this difficult to work and figure out. For starters the; instructions are vague, for a first time user. 2ndly, In order to begin calibration, you have to immerse meter in suggested liquid and wait for a stable display, to continue. If you’re able to see the video I posted, you’ll see reading hasn’t stabilized and we’re going on Day 3. Yes, it’s been sitting in the same 7.0 solution for 3 days. I plan to ask for a refund please. I need this for work and it has to be accurate. Not worth the $. Search continues.

Easy to use, but the instructions make no sense. Should have included ORP calibration fluid.

This pen is very precise when calibrated after trying three Types of pens this one is the best one