Silicon Hydroponics Benefits

The term silicon evokes mental images of silicone caulk and silicon valley techno plastic hocus pocus. Silicon is not silicone. Silicon is a naturally occurring substance, silicone is not natural but synthetic. Silicon is an element on the periodic table. It one of most abundant elements in nature, second only to oxygen. It is a naturally occurring element found in soil and works its way from there through the plant and animal kingdoms.

Commercial Nutrient solutions do not contain silicon in any viable quantity, It must be added separately.

Benefits of Silicon to Hydroponically Grown Plants

Run off from soils contains aproximately 400 ppm of silicic acid, which is readily absorbed by plants in nature. Plant tissues of soil grown specimens contain approximately 10% silicon [dry weight], which is fairly close to the dry weight of phosphorous and manganese.

It is present in all soil borne plants, It strengthens cellular walls, improving the plants tissue strength, overall health, vitality and productivity. Silicon enables plants to cope with toxic levels of certain elements such as manganese, iron, phosphorus and aluminium as well as deficiencies in zinc. It improves drought and heat tolerance and increases plants resistance to pests and pathogens. Without silicon – plant life as we know it could not exist.

6. Stems of certain plants, particularly solanaceous [Potatoes, Tomatoes, Peppers, Eggplants] are more woody than usual and at times hollow.

Hydroponic nutrient solutions do not contain silicon in any viable quantity, which is a primary reason many hydroponic plants are structurally weaker and more susceptible to many ailments. The solution one would think would be to simply add silicon in one of its forms to the nutrient feed. It is not however that simple.

Adding Silicon to Hydroponic Solutions

In order to remain soluble silicon, in its natural form, requires a relatively high pH, at least 7 – preferably higher. In an insoluble format it reacts with other elements in the feed and would generally lead to a nutrient deficiency of other essential elements. It has been demonstrated that Silicon {Si} at excessive levels causes an adverse reaction with iron and zinc.

In nature, Plants absorb Silicon as monosilicic acids, in hydroponics the most widely used form of Silicon is soluble Potassium Silicate which is sold commercially under various trade names.

Commercially processed Silicon, designed for hydroponic applications can be administered to plants in several ways.

1. The easiest, although not necessarily the best method is using soluble silicate additives. Soluble silicate additives are mixed into your regular nutrient feed and administered to the roots. Be aware however that some research indicates that when the ideal levels of silicon is exceeded there is a negative effect via interactions with other elements in the solution.

2. The most effective method and perhaps the most trouble free, in my opinion, is a foliar spray applied to the foliage periodically. It does not interfere with the nutrient solution and does not require pH adjustments..

3. A third method is a growing medium – Diahydro – comprised of fossil algae shells that contains over 90% silica. The silica is gradually released throughout the growth cycle. I’ve used diahydro as a top dressing for coco coir and vermiculite-perlite.

Diahydro needs to be replaced with each new grow cycle making it costly to use solo. It is pH neutral.

Diahydro is a trade name for high silica diatomaceous earth, other brands are just as good, but be certain they are suitable for hydroponic use and have no additives, larger granular sizes of food grade diatomaceous earth are best for hydroponics.

Another Silica Based Media is Higromite. Higromite is a silica based mineral rock. sometimes used as a hydroponic grow medium.. Silica is not taken up directly by the plant when higromite is used, but gradually absorbed by plants as a result of microbial activity . Higromite naturally facilitates the slow release of silica for uptake by the plant in a hydroponic system. It has advantages and disadvantages. See: Higromite