I love my Hanna 4 in 1.....you probably do have the 4 in 1 unit Ph, EC, TDS and temperature. Most people forget the temperature counts too...lol

You do need to have the proper calibration solution but it's easy to calibrate and it holds calibration just fine if you store it properly. It is a scientific tool and should be treated with the respect any scientific tool deserves. The calibration solution 4.0 can double as the storage solution as well. It's good to have their cleaning solution to give it a dip after each use and keep it clean before storage. There should be a small sponge in the bottom of the cap that will keep the tip moist. If the tip dry's out it could damage the unit and tips are about 45 bucks each.
Zandor Reviewed by Zandor on . picked up a new hanna unit ok well i had to get anotehr ph meter mine went on me so anyhow.... i got the 3 in 1 unit they offer, i got it today and im having a bitch of a time getting it calibrated....shit im even havinng a hard time to get it to turn on, it seems that you really have to push the buttons on it hard to get it to respond im guessing cause its new and needs to break-in how are you guys calibratign yours? what solution you using....please elaborate!!!!! thank you Rating: 5