Phal. gigantea growth rate?

[Bunch_Of_Roots]

I know it grows slow, but what is it's typical rate of growth based on your experience/ observation? The largest, individual leaf span on my plant is about 6-7 inches. It is pushing out a new leaf, but it has been growing for over two months and it is only about 3 inches...

It is currently potted in pure sphagnum moss in a net pot. All roots appear to be healthy. I brought it outdoors since last week to give it some fresh air and larger temp. variance, and more light. The humidity ranges from 50-80%. Temp. ranges from low 60s-low/mid 80s. It gets fertilized about once a week with very diluted fertilizer.

Any advice and cultural tips would be much appreciated!