Question
Hi I have a nepenthes lowii what has white blotches on one of the leaves the plant is about 10inch high and now with small leaves about 5inch but still pitching with 6inch pitchers. The nepenthes is in the greenhouse in full sun with bubble wrap over the greenhouse to shade it a bit. It is in live moss and Perlite and is moist all the time and temperature is 10c at night and up to 30c in the day and it growing with all my other highlander nepenthes.

Answer
First, I'm not exactly sure what your question is because you didn't specifically ask a question.  I'm assuming that you submitted the information in regards to the white blotches and want to know why they occurred.  If this isn't correct, please let me know.  Because of the volume of message we receive, it's easier to respond to a specific question rather than general statements.

Without seeing a photograph of your plant, I can't say for sure what the white blotches are.  I'm not sure if it's true white, which might suggest one type of issue, or tan, which might suggest a different type of issue.  I'm also unclear if it's occurring on an older leaf or on a newer leaf.  

For now, I'm going to assume it's on an older leaf, and the blotches are tan rather than true white.  

Sometimes older leaves will discolor as they age.  This is completely normal and has no indication on the overall health of your plant.  Nepenthes lowii is one of the slowest growing Nepenthes.  Leaves generally last a lot longer than other plants.  However, when a leaf comes close to the end of its life cycle, it will stick out like a sore thumb because the plant doesn't have sufficient newer leaves to cover it up.  

Warm temperatures can also cause the discoloration.  You mentioned that the temperature typically rises to 30癈.  This is considered rather high for lowii.  They can tolerate those temperatures for a short time, such as an hour or so, but the day temperature should ideally be between 20?25癈.  Temperatures of 26?and more are considered a hot day for this species.  At these temperatures, leaves will age more quickly, hence the discoloration.  Your nighttime temperature is perfect.  

So based on the information you provided, the discoloration on older leaves is normal.  It's not wide spread and is affecting only one leaf.  Overall you plant seems healthy.

If my assumptions about your plant is inaccurate, please write back with more specifics about your plant and a photograph.  

Good growing!
Jacob Farin