@CharlesD - I grow most of my collection grows outdoors from late spring through early fall, depending on the weather in Northeast Ohio. During warm weather, most of my paphs receive the following care: morning sun followed by bright shade for the remainder of the day, and watered 2-3 times a week, depending on rainfall. This summer, I experimented with a time-release fertilizer by Greencare due to the intense rainfall early in the season limiting my ability to fertilize. Greencare makes a MSU style slow release fertilzer. Once nighttime temperatures consistently drop into the low 50s/high 40s, I move the plant indoors under LED lights with a 11-13 hour day/night cycle. Watering is reduced to 1-2 times per week, with fertilizer targeting 80-100 ppm nitrogen - I rotate K-Lite and Peter's Excel. I also flush with plain water every 4-6 weeks. In the winter my indoor grow room, daytime temperatures are in the mid-70s, with nighttime temperatures in the mid to high 50s. My indoor water source is reverse osmosis (RO) water with 10-20% well water added back. In the summer, I use well water outside. While the water quality is ok, it is not great. the rain balances out any water quality issues I have.
I prefer Kiwi bark but shipping cost have tremendously increased the price. At the moment I have a surplus of Orchiata that I am working through. Until a few years ago, I was using Rexiux orchid bark, and it was just fine also. Rexius does not last as long as Kiwi or Orchiata, but I
typically repot before the mix breaks down. I aim to repot my Phrags and non-multifloral paphs every 12-18 months. My fix is bark, perlite, and charcoal. Some times I throw in oyster shells. I think it helps; and if it does not, it certainly is not hurting anything.