This picture linked below is interesting. Note the banding, which is very obvious but if we compare with LasVegan's second picture in the first post, there is a suggestion of banding there too. The suggested cause is
possible water stress. If fluoride toxicity looks the same as is implied, then can that be ruled out? Is the water fluoridated in Las Vegas?
The medium in LasVegan's pot looks dry to me but it's hard to be sure from a picture - if the pot is light when picked up it would suggest it is too dry though.
http://www.apis.ac.uk/effects_...
Regarding fertilizer, there already is some in the potting mix (the little green balls). I wouldn't add any more. If the plant is indeed too dry that can make it worse.
