Calcium Nitrate 15.5-0-0 Fertilizer - Greenhouse Grade Plant Food

In this review of Cz Garden Supply Calcium Nitrate 15.5-0-0, the bottom line is simple: this is a straightforward, highpurity water soluble nitrogen and calcium source for growers who need reliable calcium supplementation and steady nitrogen delivery. It is best for hobbyists and small commercial growers using hydroponics, drip irrigation, or soil who want a greenhouse grade product that dissolves cleanly. The product stands out for its purity and usefulness as a supplemental feed to prevent calcium deficiencies, and the resealable pouch makes repeated dosing easy.

Key Features

• High purity formulation: The greenhouse grade blend dissolves cleanly into solution so it does not leave an oily skim that can clog irrigation lines or sit on roots.
• Nitrogen plus calcium: With 15.5% nitrogen and 19% calcium, it supports vigorous green leafy growth while supplying calcium for fruit and flower development.
• Water soluble: Fully water soluble for use in hydroponics, DWC, NFT, drip systems, or soil feeding without gritty residue.
• 321 feeding schedule compatible: Works with common feeding routines and integrates easily with drip irrigation and flood and drain systems.
• Resealable packaging: The heavy duty resealable pouch keeps remaining product dry and allows precise pouring for repeat applications.

Who It's For

This product is aimed at indoor gardeners, hydroponic growers, and backyard vegetable producers who need a dependable calcium boost in addition to steady nitrogen. It is particularly useful for tomato growers concerned about blossom end rot and for anyone running drip or recirculating systems where clean, fully soluble nutrients are essential.

Growers who rely on complex allinone nutrient lines or who need micronutrient blends should look elsewhere, since this is a focused calcium nitrate fertilizer and not a complete multipart nutrient. Users seeking organically certified calcium sources should confirm suitability for their program, as this is presented as a high purity, greenhouse grade mineral fertilizer.

Pros & Cons

Pros

• Dissolves nicely and stays clear, helping avoid clogged emitters and residue on roots.
• Provides both calcium and nitrogen for balanced vegetative growth and stronger fruit set.
• Works across hydroponic setups and soil applications with a simple feeding schedule.
• Resealable pouch makes storage and measuring convenient for repeated use.

Cons

• Focused formula means growers still need a complete nutrient program with other macronutrients and micronutrients.
• Some customers reported mixed results for rot prevention, so outcomes may vary with overall nutrient balance and plant health.

Specifications

Product type	Calcium Nitrate fertilizer
Nitrogen content	15.5%
Calcium content	19%
Form	Water soluble, greenhouse grade
Packaging	Resealable heavy duty pouch (18LB available)
Intended uses	Hydroponics, drip irrigation, soil, coco, DWC, NFT, flood & drain
Country of origin	USA

Our Verdict

Cz Garden Supply Calcium Nitrate 15.5-0-0 is a practical, high purity calcium and nitrogen source for growers who need a clean dissolving supplement. It is good value for hobbyists and small commercial setups that already manage other nutrients and want a reliable calcium feed to reduce deficiencies and promote leafy growth and fruit development.

Frequently Asked Questions

Can this be used in hydroponic systems?
Yes. It is fully water soluble and suitable for hydroponics, DWC, NFT, and drip systems when used as part of a complete feeding program.

Will it prevent blossom end rot on tomatoes?
It supplies calcium which helps reduce blossom end rot risk, but results depend on overall nutrient balance and watering practices.

How is it packaged for storage?
It comes in a heavy duty resealable pouch designed to keep unused product dry and easy to pour for later use.