mold on S/H media

[Niki]

I just moved one of my Phals to S/H three weeks ago. It seems to be doing fine, however I just noticed that there is something airy and white (which I am assuming is mold) growing in the media. I can see this stuff on the S/H media on inside the container as well (some of the whitish stuff is sticking out of the drain holes). I looked at the orchid last week and there was nothing on the media.

Oh, I only use distilled or RO water for the plants, so it shouldn't be mineral built up. Also, I soaked the pellets in RO water for 48 hours, changing the water 3 times in the first 24 hours, and once in the last 24 hours to help clean it out. I did not use calcium nitrate or magnesium nitrate with my soak, however. Could what I'm seeing just be mineral deposits or is it likely mold??

We've been hit really hard with thunder storms/hail/rain/tornados for the past two week and have had very high humidity (80-95%). I usually leave the window cracked open to give my orchids airflow, but haven't been able to do this lately due to all the bad weather we're getting, so I'm wondering if that's the reason.

The plant otherwise looks really good.

What is the best corase of action at this point? Should I just spray with Phal 20 to be safe? If so, should I just spray it once and see what happens, or should I spray it once, wait 24 or 48 hours, and spray it again?

Should I repot? (in which case I'd take it out of the pot, spary it, and repot into clean media)

What is the best way to avoid mold in the future? I'm guessing that adding a few drops of bleach to the S/H media is not a good idea, but wanted to double check with you all.


Thanks
Niki