Some observations from keeping these plants at lower humidity levels – ~70% vs. 96%
All last year, I kept my plants at humidity levels nearing 100%. Plants grew large leaves, and were very lush. But the leaves were thin – resembled submersed growth and were prone to melting when they touched a surface or another plant.
By creating a little bit of a gap in the lids, I’ve lowered the humidity levels down to near 70%. The goal was to encourage the plants to have thicker leaves and to mitigate the melting problems. The results from the last few weeks are pretty obvious. By lowering the humidity down to near 70%, some of the plants lost their leaves, albeit slowly. New leaves coming in are shorter, thicker and aren’t prone to melting.
Take a look at the difference:

7 Weeks after being placed into the lower humidity setup.

The leaves are shorter, thicker.
Additionally, several plants flowered during this same period. Weather that was caused by stress, or the lower humidity induced flowering is uncertain since I don’t have many controls. However, here are three cases:
Case #1
The C. ideii spathes I’ve got pictured in this blog, is one of several pots and only the one in the lower humidity condition flowered. However, lighting levels are also a little stronger in that low humidity setup.
Case #2
The same is true for the C. pygmaea. Again, placed in the lower humidity / higher light setup, the plant flowered.
Case #3
Recently, I placed a C. usterenia in the lower humidity/higher light setup and it TOO is throwing up a spathe. Several clones of that same plant are in the higher humidity setup, and while they’re larger plants, they have yet to throw up any spathes.
Case#4
This one is slightly different from the above cases, where the lighting levels remained the same, but the humidity levels were dropped. Soon after I dropped the humidity levels in the previously high humidity setup, my C. usterenia x walkerii hybrid started throwing up spathes.
Conclusion:
While this is not by any means a definitive conclusion, there is strong anecdotal evidence that moving the plant from a high humidty setup to a lower humidty setup, induces flowering.
Additionally, as a by product, the glass doesn’t fog up any more and I can peer into the tank without opening the lid. However, evaporation is also up and I find I have to top off the water much more frequently.
Ghazanfar Ghori Observations