I'd think about switching to an organic soil, as it looks almost like your soil could be leading to the wilting going on on your leaves. Those fertilizers that brag about delivering a payload of nutrients over 6 months, or whatever, are generally intended for much more hearty outdoor plants. Using that kind of soil can be overkill for some cannabis varieties. Maybe think about doing more periodic flushes with a neutral pH water, and possibly even some mild dish detergent on one of the flushes. This helps the water to permeate the soil easier, and can help prevent nutrient lock.

Organic soil is generally cheap, and many brands are perfect growing mediums for cannabis. Many of them are also pretty dense, and could use some aeration added to the mix. You want the roots to be allowed to breathe, and soggy soil pretty much inhibits that. Regardless, one of the cardinal rules of growing your own medicine implies that you are careful with chemicals and overbearing nutrients. Add too many chemicals, and you no longer have organic medicine...you just end up with a chemically induced mess of harsh tasting - albeit large - buds.

Best of luck to ya!:rastasmoke: