Potting technique leading to crown rot

[Sunshine Peony]

Hi I have a question regarding crown rot and the potting technique that may lead to it / prevent it.

I have a few phals. Two small phals came in moss and two large came in bark.

I repotted the ones in moss into a ~60% moss, ~40% bark mix. The ones in bark were repotted in bark/perlite/charcoal. Of the ones in moss, one was ok and one had a old dead leaf that wasn't visible from above the moss that had dried/blackened. One of the two phals in bark had a black spot on the base. The other was fine. I treated the black spots of the ailing plants with listerine and cinnamon.

When looking around the web which includes this site, repotting seemed simple-just unpot, cut and treat bad roots, and fill pot with orchid mix. I'm growing the orchids windowside on humidity trays. A slight breeze is provided by a air purifier angled in their direction. I water when the skewer I put in each pot gets mostly dry.

In the past I had one orchid which developed mold and expired no matter what I did and how loosely I packed the potting medium (previously just moss). As a result, I'm quite paranoid about rot/mold growing so a week or two after repotting, I took the repotted orchids out of their mixes and checked on the condition of their roots. I found that the phal in bark with no rot now had a bad root and a black base. I treated with listerine and cinnamon and angled the plant so that the base had a gap under it so no damp bark would come in contact with the blackened spot and proceeded to fill the rest of the space around the roots with mix.

I noticed one of the repotted mini phals had a yellowing leaf and upon removal of its bark/moss mix saw the similar thing occuring as the larger phal. I treated the blackened base and left a gap around the base of the orchid with some bark and filled the rest of space with moss/bark.


Sorry for the long description above of my situation. My questions are below.

Why can other people repot and have wet media touching the base of the orchid (The base below the first set of air roots) and not have a problem? It is obvious that the middle would have the most difficult time drying and I am sure others encounter this issue. Is it my potting technique?

I already cut slits in the sides of the plastic pots holding the orchids and the roots and media adjacent to the slits dry very quickly leaving them white the next day. Is this bad that they stay dry so long btw waterings?

Did I do the right thing by leaving space below the base of the orchid? I've seen it recommended to level the whole orchid below the edge of the pot and just fill with media but that just led to rot in my case.