Grow-Genius Mono-Silicic Acid (40% Silica)

Grow-Genius Mono-Silicic Acid is a 40% w/w monosilicic acid concentrate from Grow-Genius in the UK, and it's back in Australia. Quick Bloom Lights stocks it in Sydney, direct from Grow-Genius. It gives your plants silicon in the form roots and leaves can take up straight away. It's strong enough that you dose it by the drop: 0.3 ml per 10 L of feed.

40% MSA

w/w monosilicic acid, 21% Si

0.3 ml / 10 L

root feed dose

~3,333 L

of feed from 100 ml

pH neutral

no pH correction needed

Why growers add silicon

Silicon isn't in most base nutrients, and plants in soilless media like coco, rockwool and hydro get almost none from their water. Plants take silicon up as monosilicic acid and lay it down in their cell walls. Published plant science links a good silicon supply to:

Stronger stems and leaves, so plants hold up heavier growth and handle training.
Better tolerance of heat and water stress, the kind of pressure a tent sees in an Australian summer.
A tougher leaf surface, one of the plant's own physical defences against fungal and pest pressure.
Better nutrient and water use, which means more growth from the same inputs.

Silicon supports the plant's own structure and resilience. It isn't a pesticide or fungicide and doesn't replace good climate control, airflow and hygiene. It makes a well-run grow stronger.

Why monosilicic acid, not standard silica

Most silica additives are potassium silicate. It's cheap and it works, but it's strongly alkaline, so it pushes your pH up and has to go in the reservoir first. Plants also can't use it until it breaks down in the water. Monosilicic acid is the form plants actually take up, so you don't have to wait for that step.

Potassium silicate

Alkaline, raises pH and needs correcting. Dosed in whole millilitres per litre. Has to go in before other nutrients, and the silicon has to break down into a form plants can use.

Grow-Genius Mono-Silicic

pH neutral. Dosed at 0.03–0.05 ml per litre. Grow-Genius directs it to go in after your other nutrients. Delivers silicon already in the form plants take up.

Why we recommend Grow-Genius

It goes further than it looks. At 0.3 ml per 10 L, a 100 ml bottle makes about 3,333 L of feed — more than a year for most home growers. Silica additives vary widely in their recommended dose, so compare the cost per 1,000 L of finished feed rather than the price on the bottle.

It's easy on your setup. It's pH neutral, so it won't throw out a dialled-in reservoir. Grow-Genius states it's compatible with mycorrhizae and bacteria-friendly growing techniques at the recommended rates, and readily biodegradable at 95% over 28 days (OECD Test Guideline 301F).

It was already a proven product here. Grow-Genius say it was stocked in 29 Australian stores before a change of distributor took it off shelves, and growers kept asking for it. That's why it's back.

It's a concentrate. Measure, don't pour. At 0.03 ml per litre, a 10 L watering can needs 0.3 ml, which is a few drops. Use a 1 ml graduated syringe, and wear gloves and eye protection when you handle the concentrate. Dosing charts are on each product page, and the Safety Data Sheet is available to download.

How to use it

Root feed (hydro, coco, soil): 0.03–0.05 ml per litre (0.3–0.5 ml per 10 L). Weekly at minimum, and up to every feed.
When to start and stop: from seed germination or cutting propagation through to a few weeks before harvest.
Foliar spray: 0.5 ml per litre (up to 0.75 ml per litre on woody-stemmed plants). Spray weekly to fortnightly at lights-off or in low light. Stop foliar sprays at early flowering on species with dense or compact flowers.
Mixing order: add it to the reservoir after your other nutrients, as Grow-Genius directs. No pH adjustment needed.

Safety Data Sheet

The concentrate is classed as a flammable liquid and causes serious eye damage. Store it cool, upright and tightly closed, away from heat and flame, and out of reach of children. Download the Grow-Genius Mono-Silicic Acid SDS (PDF) →

FAQ

Other 40% mono-silicic acids are cheaper per bottle. Why pay more?

Check the dose on the label. Divide the bottle price by the litres of feed it makes at its own recommended rate. Grow-Genius at 0.3 ml per 10 L makes about 3,333 L from 100 ml — work the same sum on whatever you're comparing it to and you'll see where each one actually lands.

Can I use it with my current nutrients?

Yes. It's pH neutral and goes in after your base nutrients and additives. Check pH and EC as usual once everything is in.

Do I still need it if my nutrient already has silica?

Check how much silicon your nutrient has. Most base nutrients contain little or none. If you already run a potassium silicate additive — Athena Blended Balance, for instance — pick one silicon source rather than stacking both.