KRPLUS Water TDS Meter The lightweight and portable size of the TDS water meter allows you to easily carry it with you, and measure it anytime, anywhere. Test the purity of drinking water to ensure it's healthy, monitor if Reverse Osmosis RO System works properly, whether filter need replaced, maintenance aquarium, hydroponics(test nutrients) and pool etc. This TDS meter is ideal for all water purification applications, thus to check whether your water filter is doing its job right and when to change the filter. It is very easy to use; all you need to do is to put it in the water and test. The most significant advantage of the KRPLUS TDS Meter is that you do not have to take any readings and do calculations using mathematical formulas. You get immediate results. Tds water testing meter is ideal for all water purification applications such as, Drinking water, Water filtration and purification, Hydroponics to test nutrients, Colloidal silver, Aquariums, Pools and spas.