★★★★★
Fixed my leaf issues within two weeks
I started using this calmag after noticing yellowing and weak growth within about 2 weeks it had improved leaved firmed up and colour improved again
Free Shipping Over $70
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Cal-Mag Hydroponic Nutrients Fertiliser
Price range: $36.00 through $46.70
High-strength CAL-MAG for fast-growing, heavy-feeding plants.
✅ Chelated Calcium & Magnesium for rapid absorption
✅ Helps prevent blossom end rot, tip burn & stunted growth
✅ Double the strength of standard Cal-Mag formulas
✅ Used by commercial hydroponic growers
Australian Owned & Manufactured
Free Shipping Over $60
Boost Plant Growth
CAL – MAG
NPK 4-0-0
Our Complete Grow CAL-MAG is made from a special blend of chelates and mineral nutrients for effective and fast absorption by plants.
Analysis
- 🧪 Calcium – 6%
- 🧪 Magnesium – 2%
- 🧪 Iron EDTA – 0.1%
- 🌿 Plus all trace minerals
Complete Grow Cal-Mag is a concentrated Chelated Calcium and Magnesium solution which improves the overall health of the plants. It assists fast-growing and heavy-feeding plants to uptake the required nutrients. It also helps prevent blossom end rot, tip burn, poor setting, and stunted growth.
Double the strength of other Cal-Mag products. Made and used by commercial hydroponic farmers using high-grade chelated fertiliser.
Direction
Apply 0.5 to 1ml per litre of water. Can be used in both grow and flower stages.
Reviews
5.0
★★★★★
Based on 3 reviews
★★★★★
Fixed my leaf issues within two weeks
I started using this calmag after noticing yellowing and weak growth within about 2 weeks it had improved leaved firmed up and colour improved again
★★★★★
definitely helped
Wasnt sure if i needed this, but definitely helped my plant. Growth looks healthier now
★★★★★
Did exactly what I needed it to
Started using this after my plants started showing blossom end rot
in a couple of weeks the new fruit came through clean and haven't had it since
Best For These Plants
Prevents Blossom End Rot & Tip Burn
Supports Strong Growth & Nutrient Uptake
How it Works
Mix 0.5–1ml per litre of water
Feed Your Plants
Watch Them Thrive
Calcium & Magnesium Support
Prevent Deficiencies & Power Performance
Stop blossom end rot and tip burn before they start. Our professional-grade Cal-Mag ensures perfect nutrient balance in coco and hydro systems, safeguarding your harvest and driving peak plant performance.
Problem support
Helps Prevent Blossom End Rot & Tip Burn
Made for growers trying to avoid common calcium-related plant problems.
A strong choice for crops that can struggle with blossom end rot, tip burn and related deficiency issues during fast growth, heavy feeding and demanding growing conditions.
- Tomatoes
- Capsicum
- Lettuce
- Cucumber
Core use
Hydroponics & Coco
Built for hydro and coco growers who need extra calcium and magnesium support.
Especially useful in hydroponic systems, coco coir and inert media where plants often need more targeted calcium and magnesium support than a base feed alone provides.
- Hydroponics
- Coco Coir
- Reservoir Feeding
- Inert Media
Performance support
Supports Strong Growth & Nutrient Uptake
A practical support nutrient for stronger plant performance in demanding grows.
Best for growers wanting to strengthen their feeding program with extra calcium and magnesium support during vigorous growth, high-demand feeding and intensive production.
- Fast Growth
- Heavy Feeders
- Intensive Grows
See More Cal-Mag Uses, Crops & Growing Setups
Common Problems Cal-Mag Helps Support
- Blossom End Rot Risk
- Tip Burn Risk
- Calcium Deficiency Support
- Magnesium Deficiency Support
- Weak New Growth
- Fast Growth Nutrient Demand
- Heavy Feeding Pressure
- High-Demand Crop Support
- Intensive Feeding Programs
- Extra Nutrient Support
Hydro & Media Setups
- Hydroponic Systems
- DWC Systems
- NFT Systems
- Drip Systems
- Dutch Buckets
- Coco Coir
- Perlite Blends
- Rockwool
- Clay Pebbles
- Reservoir-Based Feeding
Crops Commonly Paired With Cal-Mag
- Tomatoes
- Cherry Tomatoes
- Capsicum
- Chilli Plants
- Cucumber
- Eggplant
- Lettuce
- Spinach
- Kale
- Basil
Best Situations For Use
- Hydroponic Feeding Programs
- Coco Feeding Programs
- Fast Active Growth
- High-Demand Crops
- Intensive Feeding Schedules
- Supplementing Base Nutrients
- Extra Calcium Support
- Extra Magnesium Support
- Controlled Environment Growing
- Professional Crop Production
Growth Stages Where It Helps
- Early Vegetative Growth
- Rapid Growth Periods
- High Transpiration Periods
- Heavy Feeding Phases
- Fruit Development Support
- Leaf Expansion Stages
- Ongoing Reservoir Programs
- Intensive Greenhouse Growth
Grower Types It Suits
- Hydroponic Growers
- Coco Growers
- Greenhouse Growers
- Indoor Growers
- Heavy-Feeding Crop Growers
- Reservoir Mixers
- Performance-Focused Growers
- Professional Feeding Programs
Build A Better Feeding Setup
The Foundation for a Complete Feed
Cal-Mag is the "missing link" in most feeding routines. Integrate it with your core nutrients to unlock professional-tier growth, better fruit quality, and total nutrient stability.
Works with sprayer
Compatible with key formulas
Great cart builder
Bundle-ready upsell
Why Add Cal-Mag?
Optimize Every Drop
Cal-Mag isn't just an additive—it’s an optimizer. By adding it to your setup, you ensure your primary nutrients work harder and your plants stay resilient under heavy feeding.
- Eliminates "nutrient lockout" in high-demand grows.
- Essential for Citrus & Fruit: Specifically prevents rot and blossom drop.
- Drastically improves uptake when used with a sprayer.
- The smartest way to build a professional-grade kits
GROWER’S FAVORITE
The Ultimate Everyday Duo
All Purpose Liquid
Combine the versatility of All Purpose Liquid with Cal-Mag to provide a bulletproof foundation for indoor plants, veggies, and general garden beds. Pair with Cal-Mag for a stronger everyday feeding routine across indoor plants, veggies and garden beds.
- Growth Booster
- Simple to use
- Routine Vitality
High-Intensity Performance
NPK 20-20-20 Powder
For heavy feeders and large-scale gardens. Adding Cal-Mag to your powder routine stabilizes mineral levels and supports massive vegetative growth. Use with Cal-Mag to support stable feeding and stronger vegetative growth in heavy-feeding plants.
- Commercial Grade
- Flexible mixing
- Nutrient Stability
PREVENTS BLOSSOM ROT
Targeted Support for Citrus
Citrus Fertiliser
Citrus trees are heavy feeders of both Calcium and Magnesium. Pair Cal-Mag with our Citrus Fertiliser to prevent leaf yellowing and blossom end rot, ensuring glossy foliage and heavy, juicy fruit. Pair with Cal-Mag to support greener leaves, better fruit quality and stronger citrus performance.
- Stop Leaf Yellowing
- Fruit Quality Boost
- Green Foliage
FASTEST ABSORPTION
Works With Cal-Mag
CompleteGrow Sprayer
The fastest way to fix a deficiency. Use the sprayer for a Cal-Mag foliar feed to bypass root issues and deliver minerals directly to the leaves. Use the sprayer with Cal-Mag for faster foliar feeding and quicker nutrient uptake.
- Easy application
- Instant Uptake
- Strong add-on
Bundle Deals With Cal-Mag
The Professional Grower’s Routine
Don’t just feed, build a stronger complete setup. Bundling Cal-Mag with your core nutrients gives growers a smarter, more cost-effective way to support better plant performance with fewer gaps in the routine. Bundle Cal-Mag with your core nutrients for a smarter, more complete growing setup.
- Full Setup Savings
- Precision Growth
- Complete Support
The Essential Foundation
Mix
0.5 to 1ml per litre of water.
Highly concentrated formula. Compatible with all base nutrients and hydroponic systems.
Apply
PREVENT OR CORRECT
Ditch the measuring cups. Our precision sprayer automatically mixes the perfect ratio for you. Just attach to your hose, dial in your feed, and cover your entire garden in minutes with zero guesswork.
| Feeding Level | Mix (1L Bottle) |
|---|---|
| Standard | 100ml fertiliser + 900ml water |
Want faster, simpler feeding?
Thrive
ROBUST STRUCTURE • VIBRANT GREEN
Optimizes chlorophyll production and strengthens cell walls for heavy-fruiting stability.
How Much to Mix
Cal-Mag — Mixing Calculator
Set your ml/L and litres — totals update automatically, with caps estimate.
Approx. 1 cap ≈ 15–20 ml.
Reviews From Our Gardener's
Reviews
5.0
★★★★★
Based on 3 reviews
★★★★★
Fixed my leaf issues within two weeks
I started using this calmag after noticing yellowing and weak growth within about 2 weeks it had improved leaved firmed up and colour improved again
★★★★★
definitely helped
Wasnt sure if i needed this, but definitely helped my plant. Growth looks healthier now
★★★★★
Did exactly what I needed it to
Started using this after my plants started showing blossom end rot
in a couple of weeks the new fruit came through clean and haven't had it since
Noticed healthier growth within a week. I use it in all my garden bed soils. very fast shipping have also used there all purpose liquid fertilizer combined with this have been seen great results
Ben R
Verified Buyer
This is a great fertiliser, have used for 2 weeks now and can see very good growth taking place .Will definitely get this again. I have very poor dirt where i live so this has helped my plants alot
Chloe M
Verified Buyer
Cal-Mag Hydroponic Nutrients Fertiliser
Double-strength Cal-Mag fertiliser made with chelated Calcium, Magnesium, and Iron for fast-growing plants. Prevents common deficiencies like blossom end rot and tip burn. Ideal for hydroponics or soil. NPK 4‑0‑0. Trusted by commercial growers. Free shipping Australia-wide.
High-strength Cal-Mag formula for fast-growing plants
✅ Chelated Calcium & Magnesium for rapid absorption
✅ Prevents blossom end rot, tip burn & stunted growth
✅ Twice the strength of standard Cal-Mag formulas
✅ Suitable for hydroponics & soil-based systems
✅ Made in Australia – trusted by commercial growers
✅ Chelated Calcium & Magnesium for rapid absorption
✅ Prevents blossom end rot, tip burn & stunted growth
✅ Twice the strength of standard Cal-Mag formulas
✅ Suitable for hydroponics & soil-based systems
✅ Made in Australia – trusted by commercial growers
NPK Ratio — Cal-Mag (Hydroponic)
-
N
4
-
P
0
-
K
0
-
Ca
6%
-
Mg
2%
-
Fe
0.1%
What Cal-Mag (NPK 4-0-0) Means
Chelated Calcium and Magnesium to strengthen new growth, deepen green colour and stabilise nutrient uptake in hydro, coco and soil. Double strength for fast correction and steady support.
- Stronger structure: Calcium reinforces cell walls and root tips for firm, resilient growth.
- Greener leaves: Magnesium drives chlorophyll production for rich colour and efficient photosynthesis.
- Prevents issues: Helps avoid blossom-end rot, tip burn, poor setting and stalled growth in fast-growing, heavy-feeding plants.
Read More
Cal-Mag supplies essential Calcium and Magnesium in forms plants can absorb quickly. Calcium supports strong meristems, roots and overall firmness, while Magnesium sits at the core of chlorophyll to power energy capture. Use whenever water is soft/RO, media is coco-based, light intensity is high, or feeds are heavy in potassium or ammonium which can compete with Ca/Mg.
- Add to water first, mix well, then add base nutrients and any boosters.
- Hydro/coco: use a steady low dose each feed; soil: light, regular doses during active growth.
- Look for pale older leaves (Mg) or brittle tips/poor fruit set (Ca) as signs to maintain Cal-Mag support.
FAQ
It supports cell strength, prevents deficiencies like blossom end rot or tip burn, and improves nutrient uptake in fast-growing crops.
This formula is double strength and uses chelated minerals for faster, more effective absorption. You need less to see better results.
Yes – it’s made for commercial hydroponics and works great in any system: NFT, DWC, coco, soil or drip setups.
Absolutely. It’s designed to be used in both veg and flower stages to support calcium and magnesium needs throughout the plant’s life cycle.
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