Growth Technology GT Silica

Save $2.89
Growth TechnologySKU: ADDGTS005

Size: 1 Litre
Sale price$18.95 Regular price$21.84
Bulky Item
In stock Usually shipped within 1-3 days.
ordersFast Shipping Australia Wide
samedayPremium Customer Service
discreetDiscreet Packaging

You may also need



Silicon is the second most abundant element in the earths crust making up a component of most rocks.

Plants absorb silicon from silica that has dissolved into the soil water. As you can imagine the concentration of silicon in soil water is not that high because rocks do not tend to be all that soluble.

Silicon concentration in soil water generally does not get above 20 ppm and this is the level we recommend for hydroponic nutrient solutions.

Silicon is a beneficial plant nutrient found in virtually all soils but not, until now, in hydroponic nutrient solutions.

Silicon will strengthen plant cell walls and become a barrier against water loss, fungal infection, particularly mildews, and insect and mite attack.

Silicates are very alkaline and care must be taken with its use. Always check the pH after silicon has been added to the tank.

Handling and Care

  • always wear gloves and eye protection
  • always store in a locked cupboard
  • keep away from children
  • dilute with water before adding to tank
  • safety data sheets are available

Available in 1 litre, 5.5 litre and 20 litre containers.

What is it exactly?

GT Silicon is a concentrated mixture of silicic acid and potassium hydroxide. This is often referred to as potassium silicate. Its purpose is to add silicon to hydroponic nutrient solutions.

What does it do then?

The effect of silicon comes from the fact that plants deposit silicon in their cell walls and this has the effect of strengthening the cell wall which acts as a barrier between the inside of the plant cell and the environment. The stronger this barrier the better a plant can resist attacks from insects and fungi and also the increased cell wall rigidity gives better tolerance to heat and water stress.

What’s it all about?

Silicon belongs to a class of plant nutrients termed “beneficial nutrients”. These nutrients are not totally essential to the plant but the plant will grow better if it is present. It has even been claimed that the absence of silicon from nutrient solutions constitutes a form of stress to the plant.

OK, how do I use GT Silicon?

Silicon cannot be added directly to concentrated nutrient solutions because it will precipitate from the solution and be unavailable to the plant so it has to be supplied as a separate additive. If GT Silicon is diluted in the nutrient tank at the rate of 1ml per litre of nutrient solution, it will give a concentration of 20ppm silicon, the usual Dutch recommendation.

How often should I dose the tank?

For run to waste systems, add the GT Silicon when making the nutrient solution. For recirculating systems add the GT Silicon to the tank on a weekly basis.

Any precautions?

Yes. GT Silicon is very alkaline. Always check the pH of the nutrient solution after the silicon has been added and correct if necessary. Don’t get it on your skin or clothes. Good practice indicates care should be taken. Keep away from children.

What should I expect if I use GT Silicon?

Silicon provides real benefits to plants, the main one being increased resistance to pathogens.

For use during the vegetative and flowering cycle dilution guide. 

FULL STRENGTH 5mL per litre of nutrient solution.

IMPORTANT Always dilute GT SILICA in a seperate container of fresh water before adding to the nutrient solution.

1. Add diluted GT SILICA to the nutrient solution slowly.

2. Mix thoroughly and allow to stand for 15 minutes. 

3. Adjust pH between 5.5 and 6.5


Add GT SILICA once per week


Add when preparing the nutrient solution. 


  • Improves nutrient uptake and transportation throughout the plant.
  • Increases plant resistance to fungal and insect attack by strengthening cell walls.
  • Increases chlorophyll production in the leaves, leading to better photosynthesis.
  • Increases the uptake of available C02.


Estimate shipping

Payment & Security

Apple Pay Google Pay Mastercard PayPal Shop Pay Union Pay Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

You may also like

Customer Reviews

Based on 12 reviews
Sarah H.
Brilliant product

So far I am absolutely loving this stuff! My plants are thriving and look so good!

Aussie made and cheap and effective

Thickens stems I can see that I like to use silica and after using numerous expensive brands find this to do its job efficiently

Luke H.
Silica the white leaf and plant health game changer

I've really noticed the difference since I bought my gt silica from grow kings first off the shipping was fast as !! But the proof is in the pudding here if you have white leaves often browning not long after unfurling or just general plant health is down I'd really give gt silica a go in a gt nutrient solution I didn't expect it to work this great 😵 since using all products recommended Ive seen an inch or more in height growth and a number of new leaves on plants and also you can really see the plants are loving it going from abit dull to looking like you're a full fledged botanist that everything they touch grows 🤣 honestly this stuff is a game changer THE GOOD STUFF !!

Awesome! Turns foliage lush!! 🙏

Great product, great price, great service!! Highly recommend!!, the folk at GK go above and beyond in looking after you, cheers!

Zongming L.
Definitely recommend if you have variegated plants

It stops my variegated plants from browning. Very easy to use.

Recently viewed

Related Articles

The 5 Best Hydroponic Nutrients Australia

The 5 Best Hydroponic Nutrients Australia

NutrientsTim Dennis