I have used scientific grade testing equipment for years but now that I'm retired, I am looking for suggestions for consumer grade, fairly accurate testing equipment.
I've tried weipro some other amazon monitor but the one that's been 100% for me so far was from aliexpress ph/tds controller with temp monitor
goes for around 100 bucks with shipping and does ph/tds/temp it's app controlled and has plugs to work with solenoids (ph controllers and tds based water changing systems)
the very same one sells on amazon for more than double the price
The API FRESHWATER MASTER TEST KIT measures the 4 most important levels in freshwater aquariums quickly and accurately, including pH, high range pH, ammonia, nitrite, and nitrate.