I have did my homework on both plants in there natural environments, min temp is what I'm concerned about as I doubt I will ever exceed the 95 degree max temp in their environment. It appears like the campanulate only has lows of 75 degrees in its Borneo environment, but what I have read it seems like the Bellii is more sensitive to low temps even though the philippeans get a few degrees cooler.
I have them in a 55 gallon tank, some natural (north window) & daylight 6500k fluorescent supplemented lighting. Growing in sphagnum with some orchid bark substrate. I also have a small computer fan that kicks on twice a day for circulation in an otherwise enclosed setup. I have been very successful in the past with this setup.
Anyways, The only thing I'm changing from my past growing experience is the temp, I am now more conscious of the fuel bill than I was 10 years ago. I let my house get down to 65 at night and the room the plants are in probably gets down to about 60 (just guessing) I already have it thought out that I could place a 50 watt heat lamp below the growing area, but don't want to if I don't have to.
Just looking for opinions from those who know,