Best calcium nitrate fertilizers for fertigation and hydroponics.
Calcium Nitrate Fertilizers for Fertigation and Hydroponic Solutions
Calcium nitrate is the foundational calcium and nitrogen source in virtually every professional hydroponic and fertigation nutrient program. It is the first input calculated when building a nutrient solution because calcium must be supplied in adequate concentrations before all other elements are balanced. Calcium nitrate delivers both calcium (Ca²⁺) and nitrate nitrogen (NO₃⁻) in a single, fully water-soluble compound — making it uniquely suited for recirculating systems, drip fertigation, NFT, DWC, and foliar applications where chloride-free, sodium-free inputs are required.
Not all calcium nitrate products are equivalent. Key differentiators include total calcium percentage, ammonium nitrogen content, solubility grade, and whether the product is anhydrous or a hydrated salt. Selecting the correct product for your system and crop requires understanding these distinctions.
How to Choose a Calcium Nitrate for Your Program
- Calcium content (% Ca): Ranges from 18% to 23.5% across greenhouse-grade products. Higher Ca% means less product needed to hit your target Ca ppm, reducing overall salt load.
- Ammonium nitrogen (% NH₄-N): Most calcium nitrates contain a small fraction of ammonium nitrogen. In high-ammonium-sensitive crops (strawberries, some leafy greens) or warm root-zone environments where nitrification is limited, minimizing NH₄-N is critical. Anhydrous and trihydrate forms offer the lowest ammonium content.
- Nitrate nitrogen (% NO₃-N): The primary nitrogen form in hydroponic programs. Nitrate does not acidify the root zone and is taken up in exchange for bicarbonate, which helps buffer solution pH.
- Solubility grade: Greenhouse/solution grade products are milled and screened for rapid, complete dissolution. Technical or agricultural grades may contain insoluble residues that foul emitters and filters.
- Chloride and sodium content: Must be absent or negligible for recirculating systems and sensitive crops.
Calcium Nitrate Product Comparison
YaraLiva CalciNit 15.5-0-0 (19% Ca)
The global benchmark for greenhouse-grade calcium nitrate. CalciNit is a calcium ammonium nitrate (CAN) with 15.5% total nitrogen (14.4% NO₃-N, 1.1% NH₄-N) and 19% soluble calcium. Produced by Yara in Norway to greenhouse/solution grade specification — free-flowing fine granular, 100% water soluble, chloride and sodium free. CalciNit is the most widely used calcium nitrate in commercial hydroponic and fertigation programs globally and is the standard against which other products are benchmarked. Available in 1 lb, 4 lb, 20 lb, 40 lb, 50 lb, and full pallet (49 × 50 lb bags) from Custom Hydro.
Haifa Cal GG 15.5-0-0 (19% Ca)
Haifa Cal GG is Haifa Group’s greenhouse-grade calcium nitrate, analytically equivalent to YaraLiva CalciNit at 15.5-0-0 with 19% Ca. The GG designation indicates greenhouse grade — solution-grade solubility, free of chloride and sodium. A direct substitution for CalciNit in any nutrient program. Available in 50 lb from Custom Hydro.
Haifa Cal Prime 17-0-0 (23.5% Ca)
Haifa Cal Prime is a concentrated anhydrous calcium nitrate with the highest calcium content available in a commercial fertilizer grade — 23.5% Ca and 17% total nitrogen with an exceptionally low ammonium fraction (0.3% NH₄-N). The anhydrous form eliminates water of crystallization, delivering more Ca and N per unit weight than standard calcium nitrate. Ideal for programs where minimizing ammonium input is agronomically important or where maximizing calcium delivery per kg of product is a priority. Available in 1 lb, 4 lb, 20 lb, 44 lb (20 kg), and 55 lb from Custom Hydro.
The Andersons PureCal 13-0-0 (18% Ca)
PureCal is calcium nitrate trihydrate — a hydrated salt form that is completely ammonium free (0% NH₄-N). This makes it the preferred calcium nitrate source for crops with documented ammonium sensitivity, or for growers who need to precisely control the NH₄:NO₃ ratio in their nutrient solution without any ammonium contribution from the calcium source. Manufactured in the USA. Available in 1 lb, 4 lb, 20 lb, 40 lb, and 55 lb from Custom Hydro.
Calcium Nitrate in Nutrient Solution Design
In a two-part or multi-part nutrient program, calcium nitrate is always kept in a separate concentrated stock solution (Part A) from phosphate and sulfate sources. Calcium reacts with phosphate to form insoluble calcium phosphate and with sulfate to form calcium sulfate (gypsum) at high concentrations — both of which will precipitate in stock tanks and foul injection equipment. Diluted in the final solution at working concentration, these interactions are negligible.
Target calcium concentrations by crop type (general reference):
- Tomato, pepper, cucumber: 150–200 ppm Ca
- Leafy greens, herbs: 100–150 ppm Ca
- Strawberry: 120–160 ppm Ca (low NH₄ preferred — consider PureCal or Haifa Cal Prime)
- Specialty crop: 150–200 ppm Ca in vegetative; 100–150 ppm in late flower
Calcium nitrate is also the primary tool for preventing calcium deficiency disorders — tip burn in lettuce and leafy greens, blossom end rot in tomatoes and peppers, and soft fruit disorders in strawberries. These disorders are typically caused by inadequate calcium translocation to rapidly growing tissue. Maintaining adequate Ca concentration and solution EC, combined with proper VPD management, is the agronomic foundation for prevention.
Purchase Calcium Nitrate from Custom Hydro
Custom Hydro stocks the full range of greenhouse-grade calcium nitrate fertilizers in sizes from 1 lb to full pallet. All products are solution grade, fully water soluble, and suitable for hydroponic, fertigation, and foliar applications.
