Many gardeners use hydroponic–growing plants in a nutrient solution instead of soil to grow their plants. Because the growing medium is liquid, you need to do things a little differently, especially when adding chemical fertilizers such as Miracle-Gro to your plants. The method for adding Miracle-Gro to plants directly in the soil is easier than adding Miracle-Gro to plants in a hydroponic system.
Read thoroughly the directions for adding Miracle-Gro to plants. Follow the charts, which take into account the number of plants you're feeding, where they are in the growing process and what type of plants you have, to decide the proper amount of Miracle-Gro to use.
Put half of the suggested amount of Miracle-Gro into a bottle or bowl. Mix in the total amount of water suggested to produce a twice-diluted solution. Mix well to combine the water and the Miracle-Gro thoroughly. Tom Alexander, editor of "The Growing Edge Presents ...Hydroponic Solutions," published in 2004, recommends this dilution; Miracle-Gro does not address using their plant food in hydroponics on their website.
Pour about ¼ cup of the watered-down Miracle-Gro solution into the nutrient solution. Pour the Miracle-Gro mixture around the edges of the plants' container and not directly on the roots of the plants.
Add this solution to your hydroponic plants only about once per week.
If you notice brown edges on the leaves, dilute the Miracle-Gro solution to three times the normal suggested dilution.