Ruby Slipper with brown spots

[Ray]

I don't know if any of this applies, but you never know...

I recommend against flushing or ever watering with straight RO.

When you add an RO fertilizer to pure water, the fertilizer components buffer the solution. As the plants absorb the nutrients and expel their respiratory wastes through the roots, that checmostry changes to who-knows-what.

If you add pure, unbuffered water to that unknown chemistry, it might be a pretty nasty environment that can have some pretty stressful effects on the plants, with that being simply toxicity, or enough weakening that it leaves them vulnerable to other pathogens or environemental stresses.