Ready to squeeze every last gram, gram-per-watt and flavour molecule out of your hydro grow? This no-fluff guide breaks down exactly which additives to use, when to use them and why they matter – so you can grow smarter, not harder.
New to hydro? First dial-in your A-and-B base nutrients and EC management with our complete base-nutrient guide – then circle back here for the “secret sauce”.
Amino Acids
Amino acids are the building blocks of proteins – the plant’s metabolic LEGO bricks. Supplying them exogenously frees up energy that would otherwise be spent converting nitrogen.
When to use: Early veg through mid-flower.
Pro tip: Add aminos before highly alkaline products (like silica) to protect delicate L-form structures.
Shop favourite: House & Garden Amino Treatment 250 ml
Root Boosters
Healthy roots equal healthy fruits. Root boosters combine humic/fulvic acids, kelp extracts and vitamins to ignite lateral root growth and improve nutrient chelation.
When to use: Seedling/clone stage through week 3–4 of bloom.
Explore the full line-up: Root Boosters collection
Beneficial Microbes
Mycorrhizal fungi and plant-friendly bacteria act like microscopic supply lines – ferrying water, phosphorus and trace minerals straight to the root zone.
When to introduce: At transplant and again after each medium flush or major root disturbance.
Build your army here: Microbial Solutions
Enzyme Products
Dead roots and bio-slime can choke nutrient lines. Enzyme additives “digest” this debris into plant-available carbs while keeping reservoirs sweet.
Dose: 1–2 ml/L once a week or whenever you notice browning roots.
Top pick: House & Garden Multizyme 1 L
Silica Supplements
Silica strengthens cell walls, helping plants resist heat, drought and chewing pests.
|
Product |
Use-rate |
Best for |
|
1 ml/L |
Budget, broad-spectrum defence |
|
|
0.3 ml/L |
Rapid uptake, premium crops |
Timing: Add first to the tank (it drifts pH upward) and stop two weeks before harvest.
Cal-Mag-Fe Support
Soft RO water, LED lighting and heavy fruit load all spike calcium and magnesium demand.
-
Go-to: Flairform CMX 1 L – balanced Ca, Mg plus a dash of iron to banish leaf chlorosis.
When: Throughout grow; bump dose if you spot rusty leaf edges or inter-veinal yellowing.
PK 13/14 & Flower Boosters
Late bloom is all about stacking weight and density. PK additives spike phosphorus & potassium just when the plant’s demand peaks.
Browse our range: Flower Boosters & Enhancers
Usage window: Weeks 5–7 of an 8-week flower cycle (check strain specifics).
Flushing Agents
A clean finish means sweeter produce and smoother smoke (if that’s your crop). Commercial flushes dissolve residual salts far faster than plain water.
Top choice: Crystal Clear 1 L
How: Replace nutrient solution with flush mix for the final 3–5 days before harvest.
Frequently Asked Questions
Can I run all these additives together?
Yes – just add them one at a time to your reservoir in this order: silica → Cal-Mag-Fe → base nutrients → additives (aminos, root boosters, microbes, enzymes, PK) → pH adjust.
Do microbes replace root boosters?
They complement each other. Microbes extend the root system, while boosters stimulate new root growth.
Is flushing really necessary if I use enzyme products?
Enzymes keep roots clean during the grow; a dedicated flush removes excess mineral salts from the plant’s tissues.
Final Thoughts
Base nutrients feed your plants; additives unlock their full genetic potential. Start with aminos and root boosters during veg, keep microbes and enzymes ticking throughout, armour up with silica and Cal-Mag-Fe, hit bloom hard with PK 13/14, then finish crisp with a quality flush. Follow that roadmap and you’re already ahead of 90 % of Aussie growers.
Happy growing from the Dr Greenthumbs team! 🌱
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