Why Two Bottles?
Calcium nitrate is a diva, the moment it touches phosphates or sulphates at high concentration it binds up, falls out of solution and your plants miss dinner. By packing Ca and micro-trace goodies in Part A and packing P, K and magnesium in Part B, manufacturers guarantee 100 % solubility once diluted in your reservoir. The result? Stable EC/pH curves and a feed chart that actually works.
Big Benefits
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Hard-water resilience: Many Aussie municipal supplies hover at 120–200 ppm CaCO₃. A/B systems let you dial calcium back when tap water already brings plenty to the party.
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Heat-proof mixes: Warm res temps accelerate precipitation. Separate parts safeguard solubility during scorching summers.
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Coco & RDWC flexibility: Whether you’re running high-coco blends or deep-water culture, 2-part lines handle both without extra bottles cluttering the grow room.
Choosing the Right Line
|
Grow Style |
Best-Fit A&B |
Why It Rocks |
|
Recirculating / Coco |
Formulated for high-potassium coco and fast drain-to-waste systems. |
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Flood & Drain / DWC |
1:1 ratio dosing keeps EC dead-simple in large reservoirs. |
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Organic-leaning hybrid |
Includes kelp, fulvics + amino acids for terpene push. |
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Budget grower or large rooms |
Low-cost per litre without cutting chelate quality. |
Pro Tip: Run each brand’s feed chart at 80 % strength for the first two waterings.
If you’re comparing two-part systems to more complex multi-bottle programs, The Complete 2026 Guide to Hydroponic Nutrients & Additives in Australia breaks down boosters, micros and when they’re actually worth adding.
Mixing 101 – Step-by-Step
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Fill the tank with room-temp water, note start EC.
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Add Part A, stir 30 sec until clear.
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Add Part B, stir again. Never pour both concentrates into the same measuring jug.
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Check EC – aim 1.2-1.6 mS (cm) in early veg, 1.6–2.4 mS in mid-bloom for most plants.
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pH last, target 5.8–6.0 in coco, 5.6–5.8 in DWC.
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Top-up regularly with pH-balanced water; re-set full tank every 14 days to dodge salt creep.
For strawberry growers, nutrient ratios shift as plants move from veg to fruit set—our Hydroponic Strawberry Nutrition: Ultimate 2025 Australian Guide maps exact EC, pH and A/B doses for every phase.
Product Round-Up & Brand Matrix
|
Brand |
Grow Media |
Available Sizes |
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Coco / Soilless |
1 L – 20 L |
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Hydro / Coco |
1 L – 20 L |
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Any |
1 L & 5 L |
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Any |
1 L – 20 L |
Need boosters? Pair your base with our hydroponic additives to crank up resin density without juggling extra base bottles.
Troubleshooting Cheat Sheet
|
Symptom |
Likely Cause |
Quick Fix |
|
Milky flakes in tank |
Mixed A & B concentrates |
Drain, rinse, remake feed separately. |
|
Rust spots on old leaves |
Ca deficit from soft water |
Increase Part A or add Cal-Mag. |
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Leaf tips crisp, EC climbing |
Salt build-up |
Flush with 0.4 mS water, resume feed at 75 %. |
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Sudden pH drift > 6.5 |
Bacteria bloom in warm res |
Dose 2 ml/L 3 % hydrogen peroxide, lower res temp. |
And if your plants still show weak stems or heat stress despite perfect EC, Silica for Plants in Australia: The No-Nonsense Guide to Stronger, Happier Crops explains how silica plugs the structural gaps A&B nutrients don’t cover.
FAQs
Do I need extra Cal-Mag with A&B?
Only if your tap reads under 70 ppm or you’re running LED-heavy rooms. Otherwise Part A plus Aussie water has you covered in most cases.
How long do mixed nutrients stay stable?
7-10 days in outdoor conditions where the reservoir is exposed to elements, up to 14 days in optimal conditions.
Ready to Feed Like a Pro?
Check the full Hydroponic Nutrients collection and score free shipping when your cart tops $250. Questions? Hit the team on 1800 983 006 – we’ll give you the straight answer, no fluff.
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