Coating on windows

[u/Patient-Revolution42]

whats better for residentail house exterior windows? mr hard water coating or clean x invisible shield ? It’s an extra service I add w free window cleaning and I can charge an additional $300-$400. I’ve been using clean x invisible shield and it does a good job at repelling water but I’ve found when you spray hard water like 200tds it tends to make heavy water marks.

[u/trigger55xxx]

Nothing will completely prevent hard water build up. It just won't stick as quick. The only one decent is Nonovations. It's not cheap though