what type of potting soil o.O....some potting soils have added chemicals that are toxic to animals/reptiles.....4 inches is too much substrate.....1/2 inch or less over hot spot...which should be regulated with a thermoSTAT and be at 88-90 degrees...82 is too low for a hotspot temp...what are the ambient temperatures?..whats the cooler side of the gradient?
also realize it can be days to a week before they actually shed once the eyes go foggy/gray.
What size cage to what size cage did you upgrade?....how cluttered is the new tank? remember they love closer in type spaces....wide openness isnt a good thing for BPs.
gravel and a/c filters??? can you get us picture and explain the a/c filters a bit more? your setup sounds a bit overkill just from the written description.