Can I use this in a hydroponic nutrient solution?

Yes. It is greenhouse grade and water soluble. About 1 gram per liter adds roughly 190 ppm calcium and 155 ppm nitrogen, so count that nitrogen in your recipe.

Can I mix it with other fertilizers in a concentrate?

Keep it separate from phosphate and sulfate stock solutions. Mixing concentrates causes precipitation; add each to the diluted tank instead.

How much should I apply to tomatoes?

Extension guidance cited for this product is 2 lb per 100 feet of row, applied monthly as a sidedress. Measure by weight, not volume.

Will it stop blossom-end rot?

Not by itself. It supplies calcium, but uneven watering is the usual cause, so keep soil moisture steady along with the fertilizer.

Is this a complete fertilizer?

No. It provides only nitrogen and calcium. You still need phosphorus, potassium and micronutrients from other sources.

When is the price lowest?

The best new price recorded is $29.20 at Irrigation-Mart as of November 6, 2026. Larger bags cost more per bag but less per pound.

Where can I buy the Calcium Nitrate Fertilizer 15.5-0-0 with 19% Calcium?

5 stores we checked sell it, including Irrigation-Mart, Seven Springs Farm Supply, Greenway Biotech, Inc., Amazon, RASA Garden Supply Company.

Calcium Nitrate Fertilizer 15.5-0-0 with 19% Calcium

Q: Where is the Calcium Nitrate Fertilizer 15.5-0-0 with 19% Calcium cheapest?

At Irrigation-Mart, for $29.20, as of our latest check.

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What reviewers say

4.8 / 564 ratings

Rated 4.8 out of 5 from 64 ratings. Buyers report it dissolves cleanly and works well for fertigation and sidedressing.

What people mention

SolubilityPraisedBuyers say it dissolves cleanly with little residue in drip and hydroponic systems.
Plant responsePraisedUsers report faster growth and better fruit on tomatoes and peppers after sidedressing.
Granule qualityPraisedGranules are described as uniform and easy to spread by hand or spreader.
Packaging sizeMixedSome buyers find the 25 kg bag more than they need for a small garden.
StorageCriticisedGranules can clump when kept in damp conditions, so the bag needs to stay dry.

About the Calcium Nitrate Fertilizer 15.5-0-0 with 19% Calcium

Greenway Biotech Calcium Nitrate 15.5-0-0 supplies nitrogen and calcium together: 15.5% nitrogen (14.5% nitrate, 1% ammoniacal) and 19% calcium, from ammonium calcium nitrate double salt. Spread it dry as a vegetable sidedress, or dissolve it for drip fertigation and hydroponic recipes.

Clemson and University of Georgia Extension call a calcium nitrate sidedress usually the best choice for tomatoes, at 2 lb per 100 feet of row applied monthly, and Clemson gives weighed calcium nitrate rates for peppers, okra, cucumbers, squash, melons, and cole crops. In a nutrient solution, 1 gram per liter adds 190 ppm calcium and 155 ppm nitrogen, so count that nitrogen in your recipe and keep its concentrate separate from phosphate and sulfate stocks.

It is not a complete fertilizer or a cure for blossom-end rot; steady watering matters as much as the fertilizer. Measure it by weight. Calcium nitrate from Norway, packed in Madera, California, in 2 to 50 lb sizes.