Hanna InstrumentsHI 9813-6N Waterproof pH/EC/TDS Temperature Meter Clean and Calibration Check for Growers, 0 to 50 Degree C, 9V Battery

Pros: This is a nice step up from the Bluelab Combo meter. It's smaller, fits the hand comfortably, calibrates in a few seconds with a single pH buffer and EC standard.The probe is very responsive (unlike the Bluelab), readings stabilize in a second or two in most cases, every once in a while it might take ~8 seconds.Cons: the display is big and readable but 2/3rds of it is dedicated to calibration instructions, which are practically unnecessary. It's a little annoying, I wonder if they could've used that to simultaneously read pH and EC. It also has a 'calibration check' function which I don't understand, why not just calibrate, it doesn't take any more effort. The cal-check solution is expensive, I see no reason to buy it.The EC is displayed with 2 decimals of resolution, this is nice... the pH displays 1 decimal, not so nice. I expected more resolution but didn't read the specs closely enough. It's perfectly adequate for hydroponics but two places would let you mix nutrients more accurately.The temp probe might be off by 2° but I can't say for sure because two of my working thermometers agree with the meter, my lab thermometer is 2° higher. It might be the lab one that's wrong.If you're looking to replace a blulab combo meter, you won't regret buying a 9813.

This the pH meter I would trust

I bought this meter a few months ago. It has worked great. I love the fact that it's waterproof and I don't have to worry about getting it wet. The battery has lasted thus far approx 76 days and I'm curious how long it'll go. Today the PH stopped working properly and would only read 4.4 PH for any solution it was placed in. I tried taking the battery out and recalibrating but nothing worked.I called the phone number that came on the manual for my meter and was expecting to have to wait on hold for awhile and go through a hassle to try to get a new one or repairs. But after only TWO RINGS a rep picked up the phone and ask how she could help me. I explained the PH portion of the meter wasn't working properly. She said she'd transfer me to tech support. After only a SINGLE RING a tech support guy answered. I explained the problem and he just said to email him my receipt from Amazon. I did and my new probe is on the way. I also asked for some new calibration solution and they said YES!!!THIS WAS BY FAR THE BEST EXPERIENCE I'VE EVER HAD WITH ANY COMPANY. LITERALLY 4 MINUTES ON THE PHONE and a simple email and my new probe is on the way.HANNA IS THE BEST!

Good product, it met our expectation and fulfilled our needs.

I have used many pH meters and this is by far the best. It is very stable and does not need to be calibrated often as others, It is also very water resistant and temperature compensated. Easy to set up and easy to use.

I never could get this thing to work accurately for PH/TDS. I bought it to help maintain my fish tanks and RO/DI system as test strips can be a pain.The probe arrived dry so I followed the procedure to revive it by soaking for 30 minutes in the storage solution. Then to be on the safe side I cleaned the probe by soaking for 5min in the cleaning solution. Rinsed it with RO/DI water. Calibrated it in 7.01 buffered solution. Never could get it to read higher than 7.8 ph no matter what in 8.4 ph salt water. The previous PH test tube, color chart worked better. I spent an entire evening messing with this thing.Temperature seemed to work fine.TDS - seemed flaky as can be and was getting a different reading in 1500ppm solution every time off by +/-40pmm and for the RO water that my other TDS meter was reading 3pmm, this unit read 240ppm at first!? Later after calibration it was still reading off by 20-30ppm (from what I can tell).The back battery panel had 2 different sized screws which made it a pain to open as I needed 2 different sized screwdrivers. I changed batteries with a new 9v and it would turn on for a second and then off. Had to go back to the one that shipped with the unit. You'd think an energizer battery would work in this. Guess not.Not sure what was going on, but I just never got it to accurately measure anything except temperature. Quality just doesn't seem to be there or the probe was defective. I returned this for a refund. Thank God for Amazon's return policy.

Bought this in 2011. I used it regularly for 3 years, then it sat in my basement for 5-6 years. I needed it again so I took it out, cleaned the probe, calibrated it and it is working as it should. Great device.

I have the older version of this meter and used it for years. It was needing a new sensor wand. But I saw this newer version and decided to go ahead and buy a new unit and upgrade to the latest features. It was such a great decision, because the newer unit is a dream to use and calibrate. The temp sensor and check feature is so nice to have. The screen is big, clean and readable. This meter will serve me well for many years, and I am so happy with my purchase.

Unfortunately the device is not passing calibration. Followed instructions on both the manual as well as videos created by Hanna. Due to the limited amount of test liquid, I am unable to perform more tests. I have purchased more solution and am waiting to see if that is all it was

Can't get this meter to calibrate ph, looks to be open was missing cleaning solution that was suppose to be in the box? Will be returning.