What is Reddit's opinion of HM Digital Ph-80 Handheld Hydro Tester Ph and Temperature Tester?
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2 reviews of this product found across Reddit:

It's not so much about accuracy as it is about longevity. Those yellow pH pens work, they just don't last very long at all.

HM Digital pH 80 https://www.amazon.com/dp/B00GOFXVB0/ref=cm_sw_r_cp_awdb_imm_t1_GcMWFbW9Y6WR4

Just buy that one. I own that exact pH meter and so long as you keep the electrode sponge wet with it's electrode storage solution, that pH meter will last you YEARS.

I've used that exact pH meter over 1000 times now in the past 2.5 years. My friend has owned at least 3 different pH pens in that time. One of those was the yellow one you are talking about.

It's up to you but $65 one time is a way better deal when you consider how much of a pain in the ass it will be when that yellow pH meter loses its calibration without you being aware, so suddenly you are watering with 8.0 or 5.0 water.

I use this one.

Never had an issue. I calibrate maybe once a month for sanity sake. It's a good reliable middle of the road choice.