I use it at home to wash my car every weekend and for the few cars I detail per month. It's a $15 rental charge per month and $95 every time the tank is swapped out. I would go through 4 big bags of resin( 2 refills) evfery couple months(maybe less) more with CR Spotless which cost $170. The Culligan tank lasted me 3 months and I don't just use it for the final rinse(both systems). Just got my 2nd tank. If you're just going to use it for the final rinse, the CR Spotless might work for you. Then again, he have to buy the system up front in which you don't when you rent. Culligan did say they like to swap out the tanks every 3 months, regardless if the resin is fully used or not. Not sure how strict they are about that. My resin happened to stop filtering at 3 months. I bought a cheap TDS meter.