A pesticide probably is not needed because what is wrong may be environmental. I don't see what you mean by "bleached spots" on the leaves but discoloration of leaves is usually caused by something to do with the growing conditions. A very common condition is plant chlorosis, the leaves turn yellow.

Perhaps this article may be of some help.

http://extension.illinois.edu/focus/index.cfm?problem=chlorosis

Looks like sunburn. And yes, it can happen through a window.

its also getting to be a large plant.. in a small pot ... whens the last time it was repotted ...ken