Calphos Canton Mills, Inc.
(352) 489-2563
Golden farm field at sunset
Canton Mills, Inc.  ·  Ocala, Florida

The original Calphos, straight from the Florida deposit.

Calphos is premium colloidal soft rock phosphate, mined from the historic hard rock tailings first laid down in the 1940s. It is a slow-release source of phosphorus and calcium that keeps feeding the soil for years after it goes down.

Request pricing What is Calphos?
1940sOriginal deposit
OMRIListed for organic use
Two gradesPowder & granular
NationwideTruck & rail
OMRI Listed for organic production Mined & produced in Ocala, Florida Lower silica, higher purity Bulk, totes & bags shipped nationwide
Colloidal soft rock phosphate

A phosphate that works with the soil, season after season.

Calphos is a soft, colloidal phosphate clay from ancient marine deposits. About three percent of its phosphorus is available right away. The rest is held in the soil and released slowly as roots and soil biology draw it out.

Highly soluble synthetic phosphates can leach away before a crop uses them. Calphos stays where you put it. It supplies phosphorus and calcium along with the trace minerals that come naturally with the material, feeding root growth and building fertility that lasts. Growers who care more about long term soil health than a quick nutrient spike tend to keep coming back to it.

Rich soil being scooped, showing a natural soil amendment Slow-release phosphorus & calcium
Why Calphos sets the standard

Four reasons growers keep coming back to the source.

01

Notably purer, less silica

We mine our colloidal phosphate from the original tailing ponds of 1940s hard rock mining. Those historic deposits yield one of the cleanest, most consistent phosphatic clays available, with significantly less silica than comparable products.

02

Low moisture, easy to spread

Calphos runs dry and flows cleanly through conventional equipment. Low moisture content means less clumping, more even coverage, and simpler handling in the field.

03

Standard and granular grades

Choose the finely milled standard powder or the durable granular pellets. Our proprietary binding process keeps the granules from breaking into dust in transit, then lets them disintegrate gradually in the soil.

04

Straight from the producer

Canton Mills mines and mills Calphos in Ocala. You buy from the people who make it, which means consistent supply, direct pricing, and the volume you need by truck or rail.

Aerial view of healthy green crop rows on a farm Ocala, Florida
Not a distributor. The source.

We do not resell phosphate. We mine it.

Many companies put their label on soft rock phosphate. Canton Mills produces it. Our material is mined, dried, and finely pulverized right here in Florida, then formed into granular pellets through a proprietary process we own end to end.

  • Consistent purity, batch after batch, from a single trusted deposit.
  • Producer-direct pricing on bulk, one-ton totes, and 50 pound bags.
  • Licensed in most states and shipped anywhere in the country.
Guaranteed analysis

What is in every ton.

Total Phosphate (P2O5)22.21%
Available Phosphate (P2O5)3%
Calcium (Ca)21.05%
Fineness of grind200mesh

Phosphate and calcium figures are from independent laboratory analysis (Thornton Laboratories, Tampa FL, 2025). Derived from untreated soft phosphatic clay, so trace minerals occur naturally alongside the guaranteed nutrients. A current certificate of analysis ships with every order.

Two grades, one deposit
Grade 01

Standard powder

Our finely milled powder and standard formulation. Fast to react at the soil surface, ideal for blending, banding, and building a base of long term fertility.

Grade 02

Granular

The same pure powder formed into durable, slow-release pellets. Spreads cleanly through standard equipment and resists dusting in transport and application.

Who grows with Calphos

From row crops to raised beds.

Calphos fits sustainable agriculture, turf, ornamentals, and natural growing. Whether you are correcting a phosphorus deficiency or feeding soil life for the long haul, the rate adjusts to the job.

Agriculture

Broadcast for maintenance or soil correction, or blend into a complete fertility program.

Turf

A steady phosphorus and calcium source for healthy roots and resilient stands.

Ornamentals

Supports strong establishment and vigorous growth in beds and nursery stock.

Organic operations

OMRI Listed, so it fits certified organic and regenerative programs.

Trays of healthy young seedlings in dark soil Strong roots, vigorous crops
A name growers have trusted for decades
For decades, this is the Calphos referenced in respected agricultural and organic farming literature, from Eliot Coleman to Carey Reams. It has earned a longstanding reputation among growers focused on soil health.
Canton Mills, Inc. · Producers of Calphos

Let us talk volume.

Tell us what you grow and how much ground you cover. We will help you land on the right grade and the right freight, whether that is a pallet of bags or a rail car.

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