Growing N.robcantleyi under lights

[druboi]

I happen to have a lux meter and I measured the output of my 6 tube, T8 fixture, with reflector. 20'' away, the lux reading if about 8k and about 6'' away, it is 17,000 lux. I have read several of the lighting threads and all that I can find about lighting N.truncata and N.robcantleyi. There seems to be a shortage of clear cut answers and the debate about what lighting is best is a varied and impassioned one. I know that my N. X Miranda takes quite a bit of light, but burns, slightly, under outdoor, filtered morning light. I believe this plant wants more light than N.robcantleyi. N.robcantleyi has exhibited spotting and yellowed leaves, under high light for some growers.

I am wondering what suggestions you have for me, regarding placement of my N.robcantleyi, under the 6 tube fixture. I use 40 watt 6500k bulbs. If you feel this light is inadequate, please say so and make alternative suggestions. I grow high light Sinningias and other Gesneriads, under these lights and these plants take full sun, in the wild. I am trying to avoid excess heat and unneeded purchase of new equipment, but I would be within my means to purchase any fixture my nepenthes might require, for best growth. I want them not to be burned or light deprived, and want to keep my temps low.

My ambient humidity runs no lower than 65% and is more often closer to 80% and my temps stay between 65F-75F, at all times, with a temp drop, when the lights in the grow area go off. If you have any recommendations to tweak these parameters, for the happiest N.robcantleyi, please say so. I have done my best to do my own research and feel I have what I need to do well with this species, but I
 am eager to learn from those growing more species and longer than I do. Thanks in advance. 

[taz6122]

T8's don't come in 40w bulbs. The lighting is fine if you keep the plants fairly close.

Yellow leaves are more a sign of over-watering.

Not sure what your miranda cross is but my miranda can handle 3 hours of full sun in the morning or evening and many Nepenthes can handle 4 depending on your distance from the equator.

[druboi]

My N.robcantleyi has been happily growing, under the 6 tube T8 fixture, about 8'' below the fixture. The humidity has dropped to around 60%, ambient humidity and it handles that just fine. I run a fan between the plants and the fan and I grow the plant in LFS and super coarse perlite and I use a wicking system, with acrylic yarn, run through the bottom of the pot and out the top, over a Gladware container of distilled water. I give it an occasional mist of acidifying fertilizer, diluted to about 1/16th tsp, per gallon, misted onto the foliage. The pitchers color up nicely and it has just opened it's second new pitcher, that is about 3'' long. The plant grows at a steady, medium slow pace and has shown no signs of unhappiness, with it's current conditions. It did take time to adjust and had a pitchering leaf that just stopped its development and never picked up again, while all of the leaves after it grew normally and have pitchering tips. I suspect this was a side affect of shipping stress and change in environment. It has picked up and doesn't miss a beat.