Peters Excel 15-5-15 Cal-Mag Special Fertilizer with Black Iron | 25lb (80/PL)

25lb All-Purpose Cal-Mag Fertilizer with Black Iron, 15-5-15

Alkaline irrigation water can tie up iron and other micronutrients before they ever reach the plant, undermining an otherwise sound feeding program. Peters Excel 15-5-15 Cal-Mag Special Fertilizer combines high nitrate and low phosphate with extra calcium and magnesium to work against that.

Sold as a 25lb bag, 80 per pallet, basicity 131 lbs. CCE, urea 14.0.

Key Features & Benefits

• High nitrate, low phosphate, extra Ca and Mg — an all-purpose formulation for constant, balanced nutrition.
• Complete range of essential micronutrients — rounds out the calcium-magnesium-forward NPK ratio.
• M-77 Black Iron chelating formula — for fast, efficient nutrient uptake.
• Especially effective in alkaline irrigation water — for use on a broad range of plants.
• Basicity 131 lbs. CCE, urea 14.0 — technical specification for water-quality matching.

Who Should Use Peters Excel 15-5-15 Cal-Mag with Black Iron

This fits growers working with alkaline irrigation water across a broad range of plants who want an all-purpose, calcium-and-magnesium-forward feed with chelated iron for reliable uptake.

About Peters Excel 15-5-15 Cal-Mag

Peters Excel 15-5-15 Cal-Mag with Black Iron is one formulation within the Peters Excel water-soluble line manufactured by ICL Growing Solutions, related to Peters Professional in ICL's broader Peters family.

Frequently Asked Questions

What makes this Cal-Mag formulation different from a standard all-purpose feed?

It combines high nitrate and low phosphate with extra calcium and magnesium, unlike a standard balanced formula. That combination is specifically effective when irrigation water is alkaline.

What is the M-77 Black Iron chelating formula?

It's ICL's proprietary chelating technology for fast, efficient nutrient uptake, included here specifically as a Black Iron chelate. That chelation is what keeps iron available to the plant even under alkaline water conditions.

What plants can this fertilizer be used on?

It's labeled for use on a broad range of plants, especially effective when irrigation water is alkaline. Its all-purpose formulation isn't restricted to one crop type.

What do the basicity and urea specifications mean for water matching?

This formulation carries a basicity of 131 lbs. CCE and a urea content of 14.0, figures growers use to match a fertilizer to their water alkalinity and nitrogen-source preferences. Higher basicity formulations like this one help offset alkaline irrigation water over repeated feedings.

What size and packaging is this listing?

It ships as a 25lb bag, supplied 80 per pallet, matching its basicity rating of 131 lbs. CCE. That volume suits commercial greenhouse or nursery feeding programs working with alkaline irrigation water.

How and when should this Cal-Mag formulation be fed?

Apply it as part of a constant liquid feed program, mixing it into irrigation water at each watering rather than dosing intermittently. That continuous feeding approach is what delivers the balanced nutrition the formulation is built around, particularly when offsetting alkaline water over time.