Its for the water softener that the landlord has running to soften all the water inside the house. Last year I didnt realize that the tap on the sink was water with extra salt and I had alot of nutrient burn on the plants, haven't had a problem since I quit using it. The outside spigot is supped with water before the softener. 225 approx ppm's I am going to do a side by side and see if and how much better RO at like 9 ppm works, if the 225 is decent it will save me alot of time and money, later this year I hope to be able to put a Sediment filter and RO filter on the well at my spot. Until then I am forced to get ro at the store