Silicon Additives

How to use silicon

Add silicon to the water first, stir, and let it mix before any other nutrient goes in. Potassium silicate is strongly alkaline and reacts with concentrated feed if the two meet neat. Expect the pH to rise: adjust it once everything is in the tank.

Mono silicic acid products such as Grow Genius Mono Silicic, Mills Vitalize and Aptus Regulator are already in the form plants absorb, so they work at far lower doses and move the pH much less. Potassium silicate products such as Liquid Silicon, Plant Magic Silicon, Rhino Skin and Dutchpro Silica cost less per litre and do the same job when used properly.

Where it fits

Silicon isn't in most base feeds, which is why it is sold as an additive. Use it from early growth to the last weeks of flowering in soil, coco or hydro. Growers under LED, where plants can run cooler and drink less, often see the biggest difference in stem strength.