This didn't work out of the box. It wouldn't calibrate and the display jumped wildly. This became moot after I tried to clean the lense and the glass broke. I had another of these that became faulty after dropping it in fluid.. but the glass lense was much stronger than this one was. So.. I couldn't return it anyhow.
it doesnt do what i says on the tin folks. Crap results as my friend has a proper meter he spent £80 on and even once i had calibrated the meter out the box with PH7 buffer i bought out my local hydro shop it still doesnt give exact results! always out by around .5 ! which is quite a lot depending on what the waters for!
Very easy to test my aquarium and shows results immediatly, make sure you purchase ph buffer 4 and buffer 7 with this product, as if it sits for a month then the accuracy is not correct. So I recomend getting the liquid buffers for convenience for an extra £7
Meter comes calibrated and is as simple as it sounds. Some came with buffer powder, some did not,so check with supplier as you do need to periodically calibrate these. Otherwise for less than 9 pounds product is perfect and delivery swift.