I grow my phrags in high light - enough to bloom catts & dens.
In the cooler months (inside) the tempts sit between 68 night and 74 during the day. 50 to 65% RH.
Warmer months they take morning sunshine then moved in a shadier spot. Tempts can hit above the 90's outside humidity about the same - 75% and above.
There must be some outside breeze for the higher tempts - or they come in to be cooled & fanned.
I don't use bark - it breaks down to fast. I found I couldn't keep the mix wet enough to keep them happy or mold would start.
I keep the in sphag.moss, some in plastic pots, some in clay pots. I fertilize and 3rd watering.
Keep mature phrags moist as well as the seedlings even more. Provide good air circulation.
Phrags and NOT hard to grow, they just need good moisture and decent light to bloom in.
HTH