This pH meter is recommended for several reasons. The first is that its excellent quality for the price. Note that the model must be pH testr 30. The other models (10 and 20) are not recommended. This pH meter has temperature compensation and a removable (replaceable) pH probe tip. Just do a search and find a vendor with the lowest price with shipping. You will also need a pH 4 or 4.01 buffer to calibrate your pH meter. Once you find a vendor for the meter, they should almost always have buffer for sale. One bottle of 500 ml buffer should last quite a while. Don’t bother with the little buffer packets.
Go here for more information provided by the manufacturer (Oakton).