Beautiful fat roots.

[Blueszz]

Every time I purchase a Phalaenopsis, the roots that grow for me are much fatter than the roots that grew for the nursery. They look much better than the old roots.
This leaves me to wonder what causes roots to fatten up so nicely?

I water when the medium in the middle of the pot is almost dry (skewer looks dry, but feels still a bit cold). I fertilise weakly during growth (roots, leaves, spikes).
The fertiliser I use is very comon brand in the Netherlands (Pokon Universeel) with NPK 7,3,7 with micro nutrients. I use 1/10 of the advise dose on the bottle. Advised is 10 cc /liter. My Phal's get 1 cc/liter.

(Advised 2 teaspoons/ 0.25 gallon, I use 0.2 teaspoon / 0,25 gallon).

Sometimes it gets a fertiliser with more P.

The medium I use doesn't hold as much moister as the growers use, it's also coarser. I experimented with bark only and a bark mixture with coco husk and sphagnum. It seems that the roots in bark only grow fatter.

Just a question out of curiosity.