Normally I grow my Nepenthes outdoors, but winters here are a bit too cold for the lowland species (Zone 9a). Last year, I tried putting them on a shelf by a windowsill (no supplemental lighting) and kept them in trays, but some of them did not make it through the winter. I've decided to get some grow lights to overwinter my lowland Neps this year, especially since I have more now and I'm sure that some of the ultralowlanders (i.e. bical) will not survive on a windowsill. N. gracilis, mirabilis, and maybe some of the small seed-grown species can do okay next to the window for sure, as they did fine last year.
My planned setup is to have 2 trays of lowland Neps on a plant rack with some eggcrate diffuser lining the bottom of each tray. Each tray would be illuminated by 4 bulbs. The plant rack will be in my living room, so it will be ambient humidity (which is not super high). I'm not sure how much the water in the tray will boost humidity, but I can also put a large plastic over the entire set up (and purchase a small fan as well to increase airflow).
Right now the main options I'm looking at are T5s and T8s (2 ft, 4 bulb). T5s would run about $80 for a 4-bulb fixture with bulbs included, while T8s vary from $14 for a cheap 2 ft 2 bulb fixture to $60ish for a 2 ft 4 bulb fixture. I know that T5s are supposed to give off less heat, but since I'm growing lowland Neps, wouldn't more heat be better? I don't plan on adding any extra heat to the plant rack beyond the temperature of my apartment (~65-75 in the winter) and any additional heat from the bulbs. I'm thinking of running the lights 14 hours on/10 hours off; this is based off of what I read about the 'standard' light schedule being 16 on/8 off but that they need less light in winter.
Based on this, would you suggest T5s or T8s? T8s are definitely cheaper and should give off more heat from what I've read (which is good), but T5s should provide stronger light. With fall just around the corner, I'm planning on getting the lights soon before temps drop below 60F outside. The lights would only be used when it's too cold outside, so probably from late October/early November until mid March or so, after which all plants would go back outside. Any feedback would be appreciated.