SOOO confused about humidity

[Argentra]

Ok, the main reason (I'm guessing) that he got the rot was from the substrate you were using coupled with spraying it. Repti-bark is notorious for holding TOO MUCH humidity when you get it wet and molding easily.

Here's the thing to do with a tank: Use Aspen, newsprint paper, or paper towels as substrate. Cover the screen with a foil treatment or plexiglass (NOT towels, since they harbor bacteria easily) leaving ventilation on one side. Use a shallow but wide water dish (more surface area = more evaporation) and only add a humid box when the snake is in shed. Do Not mist the tank unless the humidity really drops, since wet bedding is a major cause of rot.

Hope that helps. Oh, and while the snake is recovering from scale rot, use paper towels only as the substrate so there's no further moisture or irritation.

EDIT: Just saw your light question. Lamps are not needed, since the best heat sources for these snakes are Under Tank Heat pads or heat tape. But if you want to use one for ambient light or temp boosts, use a regular bulb of 50w or less with the lamp raised at least 8" above the top to avoid messing up humidity. Florescent lights are a bit bright for BPs.