MSU Orchid Fertilizer 13-3-15 Reverse Osmosis, Rain, Tap Water Formula 1/2 Pound MSU ORCHID Fertilizer 13-3-15 Reverse Osmosis, rain, tap (City) water formula 1/2 pound Formulated specifically for orchids by Michigan State University (MSU) 1/2 pound = 25 + teaspoons. Mix at 1/2 to 1 Teaspoon per gallon of water. Tinny pellets with fine powder. Color from off whitish/brown to whitish/blue/green. Water soluble fertilizer. Must be mixed with water. One downside to MSU is it is a moisture magnet. this can effect color some. Granular fertilizers can start to liquefy in the bag due to contact with moisture/humidity. This will vary depending on humidity and how often the container is opened. This does not mean the fertilizer has gone bad. You can still use in liquefied state.