is it alrite to use a heat lamp to add humidity to a tokay cage.also how many tokays could u house in a 65 gallon reptarium

not sure what you mean for the first question......... id say no more than a pair for the 65

I dont know much... to nothing about tokay geckos but what I would say... and double check on this... is that it would be fine as long as the temp doesnt get too high.

have a heat lamp of course, how else would you heat him?
i have a supplementary heat mat against the glass so he can get some from that too, but a heat lamp would be th ebest, but make sure it is guarded by a mesh or the gecko may burn himself