I have been wondering this and thought I should consult the great chemists. When prespraying with the hydroforce, would it be advisable to have the chemical injection turned off, and then turn it on only when you are ready to extract with the wand? My reasoning is that the acid rinse could actually be "neutralizing" the PH level of the prespray before it even hits the carpet, thus weakening it. True?
I'm sure a chemical expert will be along shortly... But yes, the acid rinse will definitely neutralize the prespray, the exact amount will depend somewhat on the relative dilutions of each.Normally the rinse does it's work AFTER the prespray has done it's job.
I've been wondering about this myself, since I often use a low ph rinse in the chemical rinse injection on my TM. If I turn off the flow meter for the rinse mix while prespraying, will that cause any problems? Also, If I turn off the flow meter should it immediately stop the mix tank solution from entering the rinse?
There is a lot more to pH and alkalinity than simply the number on the pH scale. Other factors that influence the answer include concentration, buffering and total alkalinity. Buffering tells how much a solution resists change. A highly buffered product does not change pH easily. A product without buffering will be readily changed by whatever is added to it. But the real key to this question is concentration. A typical acid rinsed is diluted about 1 :350 when it comes through your solution line. Your prespray may be getting diluted at 8:1, 16:1 even 32:1 but always much more concentrated than the highly diluted acid coming through your solution line. The influence of the acid in your rinse solution is very small. Yes, it does somwhat neutralize your alkaline prespray. But very slight. More significant influences are the pH of the water you are using. Only pure water is 7.0. Much of the city water supply we use is on the acid side. In one city the pH was 5.5 consitently. So the water you use is likely doing more neutralzing than the acid in your rinse solution.
Thanks for a great answer! If we use water softeners then that should greatly help to prevent neutralization as well Im sure, but at least after reading that, I wont feel I've "ruined" my perfect job if I forgot to turn off the rinse while prespraying. I should ask our town water guys next time Im cleaning there what the average ph of the water is too.
when ever I ran my CDS I never ever ran back and forth to the truck just to shut off the rinse to pre spray.....and it never made a difference in the cleaning......not worth worrying about.......
I've been using the Grand Slam with a ph of near 10 in combination with Matrix All Fiber Rinse with a ph of 2 for years w/o any problem. Although you are adding a very small amount of the acid rinse to the prespray it doesn't affect it's performance in any noticeable way. Also, you will be rinsing out the TLC with pure acid rinse water afterwards anyway. I've gotten excellent results with it and it leaves the carpet clean and soft to the touch when dry.
Just for the record, Matrix All Fiber Rinse I just checked the bottle and it says PH 4.5-5.5 so its not as acidic as I thought! The Fiber rinse is also a cleaner so it acts similar to a detergent rinse without all the added alkalinity! There are some new brands I want to try coming next week, I'll post the results!
