N. northiana likes alkaline soil.
Unfortunately, I can't find a piece of pure limestone 'round these parts to stick it on (I love in a desert for those who don't know). Right now, my northiana is potted in a sphag/perlite mix in a 3.5 or 4inch pot (haven't measured). I bought some horiticultural lime to correct the acidity situation, but how much should I use? The bag obviously 1) doesn't have instructions for nepenthes, and 2) is only for large scales, like 5lbs per 500 sq. ft.