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Blue-Stone Crystals

SePRO · Copper 25.2% · EPA Reg 46923-4-67690 · Insecticide Document last checked 2026-05-30

About this product

Active ingredient Copper 25.2%
Manufacturer SePRO
Category Insecticide

Full details for Blue-Stone Crystals

Source product label ↗ Open the catalog source label while the local copy is reviewed. Verify the product name, EPA registration number, and revision before use. Source safety data sheet ↗ Open the catalog source SDS while the local copy is reviewed. Verify the exact product and revision before relying on it. EPA registration data Reg. 46923-4-67690 — registry reference, signal word and status.

Applicator discussion

Nothing here is label direction — the label is the law. These are notes from other applicators, moderated before they appear. Check the labeling accompanying the product and applicable state requirements.

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According to the label From the product label

These details were extracted from this product's label PDF. The label is the law. Confirm every rate, site, restriction and safety requirement against the label before mixing or applying. Check for a state supplemental label; a product may be restricted or prohibited in a state or site even when a rate appears below. · EPA registration data for Reg. 46923-4-67690 →

Blue-Stone Crystals is a non-classified herbicide and fungicide containing 99.0% copper sulfate pentahydrate. It is designed to control various aquatic organisms, including blue-green algae (cyanobacteria), green algae, diatoms, and flagellates, as well as certain aquatic plants like water hyacinth and water willow. The product is used in various aquatic environments such as lakes, ponds, reservoirs, and irrigation systems. It can be applied via spray, drip irrigation, or through stormwater drain systems under specific regulatory conditions. When using this product, it is critical to consider water hardness and dissolved organic carbon (DOC) levels, as these can affect efficacy. Users must be cautious of potential toxicity to fish and other aquatic life. The label provides specific instructions for different target pests and application methods, including calculations for water volume and area. Handling requires specific personal protective equipment (PPE) to prevent skin and eye irritation.

Pests covered (5)
Blue-green algae (Cyanobacteria)Green algae (Chlorophyceae)Diatoms (Bacillariophyceae)Flagellates (Dinoflagellata)Aquatic plants (e.g., Water Hyacinth, Water Willow)
Areas treatable (1)
Lakes, ponds, reservoirs, irrigation systems

Application instructions from the label 5

Lakes, ponds, reservoirs, irrigation systems

Target pest
Blue-green algae (Cyanobacteria)
Location
Both
Target pest
Green algae (Chlorophyceae)
Location
Both
Target pest
Diatoms (Bacillariophyceae)
Location
Both
Target pest
Flagellates (Dinoflagellata)
Location
Both
Target pest
Aquatic plants (e.g., Water Hyacinth, Water Willow)
Location
Both

Mixing instructions 1

For pests Location Finished strength Label notes
Algae/Aquatic Plants Both Varies based on target pest and water volume Calculations must account for water volume in acre-feet and surface area in acres.

Worker safety

PPE required Long sleeve shirt, long pants, shoe covers, protective eyewear such as goggles with side shields, chemical-resistant gloves (barrier type, rubber, or nitrile, at least 14 mils thick).

Timing & weather

Use restrictions 4