Deionized Water Window Cleaning San Clemente | Why It Matters
Deionized Water Window Cleaning in San Clemente — Why It Is the Only Correct Method
San Clemente’s municipal tap water has a TDS (total dissolved solids) reading of approximately 400–600 ppm. When a window cleaner uses tap water on salt-exposed coastal glass, they are depositing an additional 400–600 ppm of mineral content on glass that is already contaminated. Deionized water has zero TDS — it evaporates completely clean.
What Is Deionized Water?
Deionized (DI) water has had all dissolved minerals and ions removed through a reverse osmosis (RO) and deionization process. The output water has a TDS reading of 0–5 ppm, compared to 400–600 ppm for San Clemente municipal tap water. When water with zero dissolved solids contacts glass and evaporates, it leaves nothing behind.
Why Tap Water Makes the Problem Worse in San Clemente
San Clemente’s coastal glass already carries Pacific salt film and marine layer mineral deposits. When a window cleaner uses tap water to clean this glass, they rinse away visible debris but leave the tap water’s mineral content behind — 400–600 ppm of additional calcium and magnesium deposited on every panel they clean. The window looks clean when wet. Within hours of drying, the new mineral deposits become visible.
Homeowners who have experienced the “clean for a day, hazy by the weekend” phenomenon have almost certainly had their windows cleaned with tap water.
The RO/DI System We Use
Our reverse osmosis and deionized water system processes municipal tap water through multiple filtration stages before reaching the glass. The output is tested to verify zero TDS before every job. We use a water-fed pole system to deliver deionized water directly to the glass surface — no contact with buckets or equipment that could re-contaminate the water.
How Long Does the Result Last?
A deionized water clean on San Clemente coastal glass typically remains clean for 2–3x longer than a tap water clean in equivalent conditions. For Pier Bowl properties, this means 6–8 weeks of clear glass after a deionized water clean versus 2–3 weeks after a tap water clean. The difference is especially pronounced on south and west-facing panels exposed to afternoon sun.
Frequently Asked Questions
Deionized water has had all dissolved minerals removed, giving it a TDS reading of 0–5 ppm. San Clemente tap water has 400–600 ppm of dissolved minerals. Using tap water to clean coastal glass deposits additional mineral content on every panel — deionized water evaporates completely clean.
Ask for the TDS reading of their output water. A genuine RO/DI system produces water at 0–5 ppm TDS. Tap water runs 400–600 ppm. If your windows look clean when wet but become hazy within a few days of drying, tap water was used.
It costs slightly more to operate an RO/DI system, and the cost is reflected in professional pricing. The result lasts 2–3x longer than tap water cleaning on coastal glass — making the per-clean cost competitive when measured by weeks of clean glass rather than price per visit.
Yes. Deionized water is safe for all glass types including LOW-E coated glass. It contains no chemicals. The non-chemical nature of DI water cleaning is one of the reasons it is recommended by most LOW-E glass manufacturers.
Need window cleaning in San Clemente? Call (949) 841-3737 for a free quote. We serve all San Clemente neighborhoods — ZIP 92672 & 92673. Address: 167 Avenida Serra, San Clemente, CA 92672.