ya man def looking like some calcium and ph spotting...i would give them a nice rinse with half tap water and half distilled water...but ph it at 6.8....give enough to lightly flush the medium, and then remove the excess water from the catch tray...i bet that water ph is low around 5.2 or something....i would water with plain water like i said half half ph'd, until your runoff is around 6.4 or so...then you can start feeding....but always mix your RO/distilled water half with tap water, this will help with ph issues and minor calcium and magnesium issues...the tap water will act like a buffer...i only use tap water and my tap water is 170ppm...my plants grow nice though with it, i had more issues using RO water
on another note, if your plants are over fed, excessive wind will cause calcium issues like your pics show...but i think its ph related to be honest