Used to buy from AD. But ended up needing too much and it became a hassle carting bottles and bottles of the stuff home. I bought a 6 stage RO/DI unit from buckeye field supply and added a pump to increase my pressure from 45 up to 70. I have three 44 gallons brute garbage cans , one for mixed salt water, one for top off and one for waste water. There all on the wheely cart things so i can move them around. Oh and everything is mounted in my garage hooked up to a garden hose.