TDS for spot free rinse

[skinnyb]

So I got me a handy dandy TDS meter in the mail today. I bought me a DI filter kit a while back and it works fantastic but I was interested to see what my actual TDS on my tap water is. I ran some from my outdoor spigot into a plastic cup and the initial reading was 138. I have heard to have truly spot free you need it to be below 50. I will test again this weekend when I hook up my filter for my weekend wash and see what it is with the filter. My question to @DFB5.0 is 138 considered extreme, from what little research I have done 138 seems to be average, but it sure does spot if I don't dry very quickly..

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[DFB5.0]

When I looked into this subject, I came across this chart -

Going by that, 138 would seem to be quite good.

For reference, demineralized water should read at 0 -

My town/tap water reads at about 92. At that level, I haven't bothered with filtration. -

 

[skinnyb]

When I looked into this subject, I came across this chart -

Going by that, 138 would seem to be quite good.

For reference, demineralized water should read at 0 -

My town/tap water reads at about 92. At that level, I haven't bothered with filtration. -

I'll take it . However I will still filter for rinse as I get really bad spots otherwise unless it's really cool and cloud and/or I dry very quickly. Drinking quality and car washing quality I guess are different things. I do know it suds pretty good in the bucket and foam canon so can't complain there. Hoping for as close to zero when I test the weekend on my weekly dose of Car Wash Therapy

 

[kilobravo]

Alex: 138 is a number I would love to have! Mine is typically 200 or a bit higher out of the CR Spotless. I presume you have not checked the output of your softener rig yet to compare with the 138? My guess is that it might push it down below 100 but I'll be surprised if your smaller softener unit will do much more but you never know until you test it.

Regarding the spotting, are you using towels only, not a blow dryer? If so, that's where I'd spend my next dollars as you can cut the drying time in half at least if not more with a leaf blower or, dedicated blow dryer.

 

[skinnyb]

Alex: 138 is a number I would love to have! Mine is typically 200 or a bit higher out of the CR Spotless. I presume you have not checked the output of your softener rig yet to compare with the 138? My guess is that it might push it down below 100 but I'll be surprised if your smaller softener unit will do much more but you never know until you test it.

Regarding the spotting, are you using towels only, not a blow dryer? If so, that's where I'd spend my next dollars as you can cut the drying time in half at least if not more with a leaf blower or, dedicated blow dryer.

Definitely blow first . But if the sun is out it's a race

 

[boB]

My tap water read about 400 (Florida, even after the softener), Publix Purified water read about 12, Walmart distilled water read ZERO. I do a final rinse with distilled, a gallon in a sprayer and get no water spots. At about $1/gallon even if I wash my Mustang each week (I don't) I would still be competitive with a good filter in a few years.

Now I plan to start using my blower but still rinsing with distilled water first.

 

[Grimmer]

I have a CR Spotless system. When I asked them about this same thing (knowing when to replace the resin), they said to Hawkeye the surface when above zero and to not let over 20ppm dry on the paint. It has been quite a while so I could be remembering it wrong and wouldn't want to put words in their mouth. Generally, they recommended ordering the resin as soon as it lifted from 0 TDS. Which allowed for a wash or maybe two until it arrives and gets swapped.

I rinse with the DI water and then still dry with a towel. using the DI water is worth it to me just to be able to take my time without rushing to get it dried before it dries by itself.

Also, of note... When I spoke with a local industrial DI water servicer they pointed out that one of the resins (I don't recall whether it was the cathode or anode...I just remember that it was the expensive one) saturates before the other one.. Meaning that once the TDS raises up from zero the remaining TDS are unbalanced (either neg or pos) and that increases their affinity to steal ions from other surfaces.

I have used DI resin up into the mid teens TDS and haven't noticed it being a problem with leisurely towel drying.

When the rain dried on my paint it made "ghost water spots" that weren't really visible when dry or casually observed (required close inspection or slightly damp paint to see them). They wouldn't come off with a clay bar, but they do polish right off. Took about 5 years for enough of them to accumulate to bug me into polishing it.

 

[Evolvd]

I started off rinsing with my CR spotless DI but soon switched over to using it for everything. I don’t have any shade when washing my car so I use the DI to foam the car and fill my buckets for hand washing. Only spots I get are from rain and the occasional sprinkler.

 

[Grimmer]

I started off rinsing with my CR spotless DI but soon switched over to using it for everything. I don’t have any shade when washing my car so I use the DI to foam the car and fill my buckets for hand washing. Only spots I get are from rain and the occasional sprinkler.

I have used DI in my wash bucket from time to time as well. If not DI then softened (the soft may leave residue, but they are a lot easier to clean off than hard water stains). Usually the soap itself is what leaves residue requiring a re-wipe if it dries.

My number 1 rule for parking is never park near any grass. About a week after I polished my car I parked next to some grass (for the shade) figuring the sprinklers wouldn't run in the middle of the day. Oops... Never again.

 

[kilobravo]

I do a final rinse with distilled, a gallon in a sprayer..

boB: I can't imagine doing that but my hat's off to ya for your determination. :-) And I will assume that your sprayer is the "pump up and spray" type as is used for spot treating weeds and not a little spray bottle.

All: FWIW, I also wash outside with a LITTLE shade on most of the vehicle. I don't use the CR Spotless water for foaming or washing but I do my best to wash as quickly as possible. I also only wash in stages with rinsing in between.

Once the wheels are done, (the paint is still dry,) I wet her down then wash the upper surfaces and rinse. One side and the front or back and rinse. then the other side and rinse, all with just house-softened rinse water. It is at this point where I hook up the CR Spotless, lower the pressure to 600psi, and give her a good rinse, taking my time and trying to "push" all the harder rinse water off the vehicle leaving the softened behind.

Finally, I pull her in the garage for blow drying. If you don't have shade when drying and your water is even remotely hard, it will be nearly impossible to avoid some spots. I typically have a few where I missed wiping a drip but no more than a couple.

Hard water is merely water with minerals (calcium, magnesium, iron, etc.,) in solution and to my knowledge, there are only two ways to remove them..distillation or ionization. (FTR, "filters" ONLY remove contaminants that are NOT in solution, i.e., they are in suspension.) As has been noted, distilled water by definition has a TDS of zero. Ionization or "softening" will never remove all the contaminants so zero TDS is unattainable with ionization.

The CR Spotless "TDS meter" is a bit deceiving and is really only for determining when it is time to change the cartridges, i.e., when it starts inching up from zero. But when it does say zero, it does NOT mean that your TDS IS zero. All zero means is that the rig is working at its designed efficiency and removing as much of the minerals that the resin can handle.

When the number gets positive, the rig has dropped below the designed efficiency and odds are, you will start having more spotting.

I have calculated that a set of cartridges will last me about one year (one wash/week,) and that is when only using it for rinsing and, the pressure is reduced by two thirds. Running the CR Spotless for foaming/washing at full pressure will dramatically reduce the time between cart replacement. If I had to guess, I would say that instead of a year, I might get four months before having to replace them.

 

[skinnyb]

The CR Spotless "TDS meter" is a bit deceiving and is really only for determining when it is time to change the cartridges, i.e., when it starts inching up from zero. But when it does say zero, it does NOT mean that your TDS IS zero. All zero means is that the rig is working at its designed efficiency and removing as much of the minerals that the resin can handle.

I just was doing research on the CR systems and realized they have that nifty little meter. The system I bought while a cheap Amazon special, the canisters are clear polycarbonate and the resin is color changing which I find very helpful. It has 3 smaller cans and I have cleaned and filled 2 of them already. The first one went from the dark navy blue to the tan depleted color first then it crept up into the second one and once the third one started changing colors, I cleaned and refilled the first 2 and started the cycle over. My thinking is as long as I keep that last can in good shape the water should be good to go. Now that I have an external meter I plan to test it before and after I rinse each time to see where I'm at. All this TDS stuff is new and very interesting to me Another love/hate thing for me on the rig I have is when I flip the bypass to filtered water, it has a built in pressure reducer to keep the system running efficiently. I can put the 15 degree tip in my Karcher 1800 and it's just enough water to keep the unit from starving. Makes rinsing take a little longer but worth it to keep the spots away

 

[boB]

boB: I can't imagine doing that but my hat's off to ya for your determination. :-) And I will assume that your sprayer is the "pump up and spray" type as is used for spot treating weeds and not a little spray bottle.

Yep, I use a pump n spray but I will post a photo of me using a little 8 oz spray bottle just to show how dedicated I am. ;)
The final spray rinse only takes a couple minutes and my garage queen only gets washed once a month or less. I guess she is not a total garage queen since she did a track night at Daytona.

 

[yoshi37]

I found an industrial water company that was willing to rent me a large-ish DI tank for about $15/month. I wash my car weekly and only need to replace the tank once a year. And that is in Southern California with my TDS reading ~<350 from the tap! I know my company no longer takes new residential customers but it might be worth checking out in your areas.

 

[Evolvd]

boB: I can't imagine doing that but my hat's off to ya for your determination. :-) And I will assume that your sprayer is the "pump up and spray" type as is used for spot treating weeds and not a little spray bottle.

All: FWIW, I also wash outside with a LITTLE shade on most of the vehicle. I don't use the CR Spotless water for foaming or washing but I do my best to wash as quickly as possible. I also only wash in stages with rinsing in between.

Once the wheels are done, (the paint is still dry,) I wet her down then wash the upper surfaces and rinse. One side and the front or back and rinse. then the other side and rinse, all with just house-softened rinse water. It is at this point where I hook up the CR Spotless, lower the pressure to 600psi, and give her a good rinse, taking my time and trying to "push" all the harder rinse water off the vehicle leaving the softened behind.

Finally, I pull her in the garage for blow drying. If you don't have shade when drying and your water is even remotely hard, it will be nearly impossible to avoid some spots. I typically have a few where I missed wiping a drip but no more than a couple.

Hard water is merely water with minerals (calcium, magnesium, iron, etc.,) in solution and to my knowledge, there are only two ways to remove them..distillation or ionization. (FTR, "filters" ONLY remove contaminants that are NOT in solution, i.e., they are in suspension.) As has been noted, distilled water by definition has a TDS of zero. Ionization or "softening" will never remove all the contaminants so zero TDS is unattainable with ionization.

The CR Spotless "TDS meter" is a bit deceiving and is really only for determining when it is time to change the cartridges, i.e., when it starts inching up from zero. But when it does say zero, it does NOT mean that your TDS IS zero. All zero means is that the rig is working at its designed efficiency and removing as much of the minerals that the resin can handle.

When the number gets positive, the rig has dropped below the designed efficiency and odds are, you will start having more spotting.

I have calculated that a set of cartridges will last me about one year (one wash/week,) and that is when only using it for rinsing and, the pressure is reduced by two thirds. Running the CR Spotless for foaming/washing at full pressure will dramatically reduce the time between cart replacement. If I had to guess, I would say that instead of a year, I might get four months before having to replace them.

Also entirely dependent on how hard your water is to begin with. I’ve been using my CR over a year now and it’s still on the original cartridges. I also use it for every part of the wash without flow reduction, not just rinsing. So far so good

 

[sox3]

I went with the Griots tank set up. Mounted it on an old Pressure washer cart, added a hose reel with 50 ft hose and short gun. Also have a TDS Meter mounted with 2 probes so I can see the in and out of the water. Able to change tips if needed too. Generally use house pressure for rinses only. This has worked well for me. Lasts about 2 yrs and that's with 3 vehicles.

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