Pro-Cal Green Planet – Calcium, Magnesium & Iron Supplement

Pro-Cal by Green Planet is the professional additive designed to strengthen your crop's structure from the roots up. This isn't just another bottle; it's the structural engineer your plants need to turn flimsy stems into heavy-duty branches capable of supporting massive buds, ensuring that your nutrient regimen is complete and effective.

Have you noticed yellowing leaves, purple stems, or slow growth just when your plants should be exploding with vigor?

It is incredibly frustrating to see your hard work stall because of a "mystery deficiency." When your plants lack essential secondary nutrients, they become weak, susceptible to pests, and unable to hold the weight of heavy flowers. Ignoring these signs often leads to nutrient lockout and a mediocre harvest that doesn't reflect the effort you put in.

Pro-Cal is the fix. It delivers readily available Calcium, Magnesium, and chelated Iron to stop deficiencies dead in their tracks. By integrating this supplement, you ensure your plants stay lush, green, and robust enough to deliver the heavy yields you are chasing.

Why Pro-Cal is essential for your grow

Think of Calcium and Magnesium as the building blocks of your plant's skeleton. If you are growing with LED lights or using reverse osmosis (RO) water, your plants are likely starving for these elements. Pro-Cal provides an immediate source of these nutrients, plus Iron, which is crucial for chlorophyll production.

Unlike generic supplements, Pro-Cal uses multiple forms of chelated Iron (EDDHA and EDTA). This means the iron remains available to the plant across a wide pH range, preventing the dreaded "lockout" that happens with lower quality cannabis fertilizers. It acts as a turbocharger for photosynthesis, keeping your leaves a deep, healthy green while thickening cell walls to support massive colas.

How to use Pro-Cal for maximum results

Using Pro-Cal is straightforward, but timing is key. It is designed to be used throughout the vegetative stage and most of the flowering stage.

1. Preparation: Shake the bottle well before use to ensure the sediments are evenly mixed.
2. Vegetative Stage: Add 1.25 ml per liter of water. This prepares the plant structure for the weight to come.
3. Flowering Stage: Increase the dose to 2.5 ml per liter of water. This is when the plant demands the most energy and structural support.
4. Mixing: Add Pro-Cal to your water before your base nutrients (like GP3 Bloom Green Planet) to prevent chemical reactions.
5. Check pH: After mixing all nutrients, always check the pH level using reliable PH meters to ensure optimal absorption.
6. Stop: Cease application during the final flush week to ensure a clean taste.

Key advantages and benefits

• Thick Cell Walls: The calcium strengthens the cellular structure, allowing the plant to support heavier buds without snapping.
• Chelated Iron (EDDHA & EDTA): Ensures iron absorption even at varying pH levels, preventing chlorosis (yellowing leaves) and keeping plants vibrant.
• Magnesium Nitrate: Provides a highly soluble source of magnesium, essential for chlorophyll and photosynthesis, boosting plant energy.
• Humic/Fulvic Acid: Acts as a natural transporter, helping the plant absorb minerals faster and more efficiently.
• Versatility: Perfect for soil, coco, and hydroponic systems, especially if you use soft water.

Care and maintenance

To keep Pro-Cal effective, store the bottle in a cool, dark place away from direct sunlight. Extreme temperatures can degrade the chelates. Always use clean pipettes or measuring cups to avoid contaminating the bottle. If you see crystal formation around the cap, simply wipe it clean with a damp cloth; do not let dried nutrient crust fall back into the solution.

Frequently Asked Questions

Can I use Pro-Cal with other nutrient brands?

Yes, absolutely. While it's formulated to work perfectly with the Green Planet line, it is an excellent Cal-Mag supplement that works with any nutrient regime.

Is this necessary if I use tap water?

It depends on your water's EC (hardness). If your tap water is very soft (EC under 0.4), you definitely need it. If you have hard water, you might use a lower dose, but the added iron and fulvic acid are still very beneficial.

When should I stop using Pro-Cal?

You should stop using it during the final week of flowering (the flush week) to ensure there are no residual salts in your final product.

Personal Experience of Pevgrow’s CEO (Alan)

I've seen countless crops suffer because growers underestimate the need for Cal-Mag, especially when making the switch to high-intensity LEDs. In my own tests, using Pro-Cal made a visible difference within days on plants that were starting to look a bit pale and tired. The stems thickened up significantly, which saved me the headache of having to tie up every single branch later in flower.

What I really appreciate about this specific formula is the iron chelation. I've used other brands where the iron precipitates out if the pH isn't perfect, but Pro-Cal stays stable. If you are growing in coco coir or using RO water, this bottle isn't optional—it's mandatory if you want top-shelf results.