Peters Excel 15-5-15 Cal-Mag Special Fertilizer can be used on potted and cut flowers. As orchids can be sensitive, we recommend consulting an orchid specialist. Also, we're not familiar with an MSU product therefore are not able to make a recommendation.
Yse, the Peters Excel 15-5-15 Cal-Mag Special Fertilizer is blue crystals per the SDS.
Unfortunately, we are unable to provide advice on cannabis treatments.