Mine is only 6 months old, but I have had to do NOTHING but plug it in and calibrate it...
Being a continuous meter, meaning it stays submerged constantly, you do not have the probe issues you see people having with the pens... which dry out after every use...
I thing they are a great product, and I would buy it over again for the $170 I paid for it....
The first couple of years the pH electrodes lasted 1 year. Then I started having trouble with them lasting even 6 months. The warranty was 1 year, so I was getting a new free replacement for each one I bought. That lasted several years. Then Hanna changed the warranty to 6 months.
Now I keep the electrode stored in my top-off water, rather than the res, and they last 10-12 months.
i don't understand the top off water part i was considering purchasing one because you can just leave the electrodes in the res. I am assuming that every time you want to check your res, you have to put the electrodes in there, like a hand held.
Yeah, the top-off water is pH adjusted water that I use to top-off the res each day. I've found that leaving the electrode sitting in that will make it last longer than when left sitting in the res. Yes, the electrodes will reach to each res, and I just put them in it, and in a few seconds the reading is stable.