Thanks for the info. Would connecting the in and out of the deionizer tank backwards the first time cause this to happen? I did connect it backwards the first time LOL. Everything seemed fine at the time, but the water coming out of my pressure washer was minimally getting deionized (like ~450ppm without to ~300ppm with). When I got the system connected correctly, I was getting down to ~20ppm. I think I'm up to ~70ppm now after 10+ washes.
I misspoke when I said the output pressure needs to meet the min require by your pw, I meant Gallons Per Minute (GPM). I'll answer your question first and come back to that.
Connecting it backwards may have been the cause of resin coming out.
As far as the TDS level being at 70ppm after 10 washes, that's certainty possible.
The higher the TDS present in the supply water, the less treated water the system will yield. At 450ppm, the resin is going to become depleted quickly thereby only producing 1/10 the amount of treated water it would if the source water was only 45ppm. As the resins become saturated, the amount of TDS present in the filtered water will creep up until eventually the input and output will be the same.
The manual for that system estimates the amount of treated water you can expect to yield with the source water containing 400ppm is approx 150 gals. That's not very much and when you consider the cost of the resin, your average cost per gallon is crazy expensive.
Here are a couple of things you can do to get the most out of the water the system will produce.
Only use the DI water for the final rinse.
There's no benefit to using it to wash and wet the car down. As long as the vehicle is kept wet, you won't get water spots from the city water. This will save you a ton of DI water.
Never rinse a vehicle using DI water without your pressure washer. You will use 3 to 4 times more water without a pw.
Buy a water meter and install it on the output side of your system. Home Depot sells one for about $10 that displays the gallons for that session as well as the total gallons since it was last reset. This will help you to be more frugal.
When you consider the cost associated with these types of systems when you have hard water, they aren't very coat effective. The water here in the PHX area varies wildly between 600-1050 ppm TDS. A home DI system cost me approx $5 per vehicle just to rinse! I sold the system and took advantage of the availability of a company here that provides DI solutions. Depending on the need of the customer,, they provide numerous sized tanks from small 10" diameter that will treat around 500 gals. all the way up to huge ones the size of a small buildings that provide hundreds of thousands of gallons before needing to be replenished. The company comes out and replaces the spent tank with a fresh one whenever I request one. The tank I use is 14" dia. and 5' tall and yields approx 1150 gals.
I pay $75 per tank and $15 for delivery/exchange. Way, way more cost effective!
Check to see if you have such a company in your area. If you're in socal, you do. They're called Purtec Water.
Back to your pw..
The system you have outputs approx 4.1gpm. Make sure this meets the min input of your pw.
