I purchased to check the PPM of our newly installed Reverse RO drinking/ice maker water...easy to use. Inexpensive..Seems to do the job .When using, will compare to distilled water which should be at 000 ppm just to verify calibration.

Very accurate used it on distilled water to check the calibration and gave it right at 1` perfect Easy hold button once reading registers., Awesome product. Even has instructions and a very nice carrying case.

Good and cheap and customer friendly purchase. Pressures good. Though written 30psi, all pressure very good.Company trying to come up, i congratulate and say them-Keep up the good work.

Good quality membrane. i purchase many time my experience is very good. its not dry membrane, it comes with AB liquid. at this price its good choice. And u have to flush First 20-25 liter of pure water to make it drinkable.

After buying a ton of other products (the pH Pen that stops working pretty fast & the pH paper strips that are really undependable) these drops were a life saver to check the pH of my nutrient water and tap water. Only after getting these drops did I realize my tap water is actually super basic around 9 and now I'm using pH down by radongrow to bring it to more acidic levels.

Though, the bottle is really really small (probably the size of your thumb) and with a few drops per test, it might not last for even 50 readings, but the readings are accurate. Use a clear glass container and if the solution is already colored, dilute with RO or distilled water (which can be bought as Inverter battery water)