how much tds is too high

[aqus]

Hi I have a black SUV. My home water is at approx 50PPM.
I am looking to buy a dionized water system like CR for quick dirt removal and let dry in winter.
So I am wondering how much TDS is too high for water spotting on a black car?
I am looking at the pricing of a CR system and resin cartridges and it seems to get very expensive even if using only for final rinse.
I wash my car with a complete towel dry or air dry once a week.
My goal is mostly a solution for winter in between full wash. With the slush and snow I can go out in a day and car is filthy when I get back. Don't want to do a complete wash but a quick pressure washer rinse and air dry till the weekend normal full wash, but afraid I will get water spots if I just rinse and let sit in the garage.
read many posts but can't find how much TDS causes water spots. I figure anything over 0 can damage. And If I rinse and let dry inside garage can it damage paint with water spots if I do a complete wash within a week?
Don't have ceramic coating just a turtlewax graphene flex coating

[Bruno Soares]

According to CR Spotless, anything over 20 TDS will spot. The water produced by their system is at 0 until the resin starts to go bad, then it climbs fast and within a couple washes it's well past that limit for spot free rinse.

[2black1s]

50 TDS seems reasonable... At least to me. My TDS ranges from 450 to 550. I'd be thrilled if it was 50.

With your TDS at 50, I would think the CR or similar system would work pretty well. At that TDS level the resin should last a reasonable amount of time before it needed to be changed.

I have my own homemade RO/DI system and I change the DI resin as soon as I see the TDS creeping up from zero, and always before it reaches 10.

As far as what TDS level will leave spots behind, I'm with you and think anything above zero will to some extent, but the severity and concern for permanent damage is pretty low. I'd do a little experiment if I were in your shoes. Clean and dry your car as you normally would, then spray some of the 50 TDS water of yours on a horizontal section, let it dry, and see how bad the spotting is. I would think the spotting would be minimal and would clean away during the next normal wash. I wouldn't expect any severe etching.

[WhiteShadow89]

According to CR Spotless, anything over 20 TDS will spot. The water produced by their system is at 0 until the resin starts to go bad, then it climbs fast and within a couple washes it's well past that limit for spot free rinse.

They used to say that and I usually go to that point; however their documentation with my unit says anything over 0 ppm could cause spotting.

OP- The official answer is anything over 0 ppm on the CR spotless TDS meter could cause spotting. Truthfully 50 ppm is very low on a TDS meter. Are you having issues with spotting? For your purposes the CR spotless system WILL spot. You are essentially rinsing off the loose grime and leaving the rest behind. As the water dries on the left over grime it will spot.

I have been using a CR spotless system for a few years now. In theory it can provide 100% spot free results from drip drying as it gives you the water to do so with; however the reality I have found in my experience is a little different. The reality is that there are other variables that prevent this. Things like grime from super tight panels (dribble points), left over grime or even contaminants that settle on your car while it dries from the environment it is sitting in can all can cause light spotting. CR spotless is a great tool for getting easy spot free results when drying...drip drying not so much in my experience if you want to avoid light spotting in some areas.


Regarding TDS in how it fits in with water spotting- TDS is the total dissolved solids of organic and inorganic materials. Examples of these materials are: metals, minerals and etc dissolved in a particular volume of water. Essentially it is anything in the water that isn't actually water. The importance of this reading for car detailing is that if you have minerals in your water when you rinse...as the water dries off the minerals etch into your clear coat causing a water spot. The severity of which depends on the environmental factors, water quality and how long it has had to etch.

If you want to incorporate a CR spotless into your wash regime go for it! I still like mine and at 50 ppm your resin will go further than someone that has a high ppm count (your resin life does vary on ppm). As far as using it solely for rinsing loose grime I wouldn't bother. CR isn't cheap and it is sort of a waste imo to use it just for rinsing loose grime. Another option if you are struggling with a spot free dry at 50 ppm is to get a good quality quick detailer (Gtechniq Quick Detailer as an example) as a drying aid. Should make quick work of fresh water spots.

[aqus]

OP- The official answer is anything over 0 ppm on the CR spotless TDS meter could cause spotting. Truthfully 50 ppm is very low on a TDS meter. Are you having issues with spotting? For your purposes the CR spotless system WILL spot. You are essentially rinsing off the loose grime and leaving the rest behind. As the water dries on the left over grime it will spot.



No so far I am not having water spot issues, just trying to avoid. I don't like to see my car real dirty especially in winter therefore was looking at a solution to take out the slush and winter dirt without doing a complete wash every day. BTW my plan was to wash off the grime with regular water and then use a final rinse on top to let air dry in garage and hoping to avoid water spots. Wanted a quick 5 minute solution until full weekend wash
Your point "You are essentially rinsing off the loose grime and leaving the rest behind. As the water dries on the left over grime it will spot." does make sense.

[WhiteShadow89]

No so far I am not having water spot issues, just trying to avoid. I don't like to see my car real dirty especially in winter therefore was looking at a solution to take out the slush and winter dirt without doing a complete wash every day. BTW my plan was to wash off the grime with regular water and then use a final rinse on top to let air dry in garage and hoping to avoid water spots. Wanted a quick 5 minute solution until full weekend wash
Your point "You are essentially rinsing off the loose grime and leaving the rest behind. As the water dries on the left over grime it will spot." does make sense.

You would spot some (light), but I would imagine those water spots would be easy enough to remove when you go to wash your car for real.

I agree that it sucks seeing your car dirty, but I would still advise you to wait until you can wash it properly. Options for dealing with winter is pretty limited (warm water washes) and 5 min options are virtually non existent unless you want to subject your car to a touchless wash or rinse to leave some level of spotting behind. Winter is just a tough time that you combat as you can. Biggest thing to me would be a strong protectant to keep your paint/clear safer during the harsher months while you can’t clean as often.

[2black1s]

I concur with the light, minor spotting left behind when you do a final rinse with 0 TDS water and let it air-dry in most real-world cases. That is also my experience.

The only way you could achieve a truly spot-free finish is if the vehicle is surgically clean and remains that way during the entire air-dry process.

[luckydawg]

I should have got my water tested for TDS while I had it checked for ph when I was still working at a nuclear plant
My tds must be around eleventy zillion-- its so bad that my solids come out the hose in chunx