I'm really curious as to what can cause this. The guides show nothing that would lead to a revelation here. This plant's leaves are browning at the edges, except for the very top leaves...that might be able to be explained ... but what can't thus far is why in several areas of the leaves there are brown/brownish yellow areas where the leaves have seemingly been eaten away entirely...like on the sides. In some cases this happens as a hole in mid-leaf. no visible pests can be seen, and a plant not more than 2 ft away doesn't display these problems. Both are in the same medium ... any clues?