Starting At: $137.00


OSA/28 provides stabilized silicic acid that instantly transforms into plant-usable form upon dilution with water. When you combine OSA/28 with other indoor growing supplements you will find that you can achieve a better yield in both quantity and quality.

  • Strengthens cell walls and increases nutrient uptake in plants.
  • Provides silicic acid in a form available to the plant to uptake.
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OSA/28 plant-available silicon (as monosilicic acid) strengthens cell walls, increases nutrient uptake, and helps plants handle all kinds of stresses. Other silicates are not bioavailable and take time+microbes to become plant available. This makes OSA/28 the fastest option for delivering silicon directly into the plant cell walls! Silicon also has a synergy with calcium in building better plant structure. Many growers see increased calcium response when feeding with OSA/28.

Indoor growing supplements like OSA/28 are manufactured by Plant Science Concepts’ staff of Ph.D. chemists in the USA using domestically sourced ingredients.

Indoor Growing Supplement Usage Rates:

Root drench: Mix 0.5ml per gallon of water every feeding from early vegetative through mid-bloom Foliar spray: Mix 4-8ml per gallon of water 1-2 times per week


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