I also had the cheap one you were talking about and your right it was a piece of crap. Since i have upgraded i have not had any issues with PH. The cheap one wouldnt hold a reading and if you shook it the reading would change. The electrode would also only last about a month. The reading on my HI98130 is solid and accurate. It doesnt change when you shake it and it also has auto calibration so when you calibrate it only takes a few seconds. The electrode will last you a year instead of a month. If you ever decide to grow hydro or grow in coco you'll need an accurate PH meter. The meter i showed you is also a EC/TDS meter so you dont need to get any other meters.