Description
United Chemical Yellow Treat² Mustard Algaecide – 2 lb Bottle (YT2-2LB-C12 / YT2-C12)
United Chemical Yellow Treat² is a fast-acting mustard (yellow) algae treatment designed to knock down stubborn yellow blooms in all pool surface types. This granular treatment is commonly used as a “rescue” or “problem algae” step alongside super-chlorination to help clear visible mustard algae quickly and restore water clarity.
Key Features
- Targets mustard/yellow algae (a common, chlorine-resistant algae type)
- Granular sodium bromide-based algae treatment (used with super-chlorination)
- Surface-safe for plaster, vinyl, and fiberglass finishes
- Non-staining formula (no copper or staining metals)
- Compatible with chlorine pools (including salt systems) and bromine pools
Product Details
- Brand: United Chemical
- Product: Yellow Treat² Mustard Algicide
- Form: Granular
- Size: 2 lb bottle
- Part / SKU: YT2-2LB-C12 (commonly referenced as YT2-C12)
- Primary Use: Eliminate visible mustard/yellow algae blooms
Dosage & Directions (Quick Guide)
- Swimming Pools: Add 5 oz per 10,000 gallons by broadcasting over the water surface.
- Spas: Add 1/4 oz per 500 gallons by broadcasting over the water surface.
- Brush affected areas thoroughly (walls, floor, steps, ladders, and behind fittings).
- Immediately super-chlorinate using your preferred chlorine shock (follow the shock product’s label for dosage).
- Run circulation and filtration continuously during treatment and clean/backwash the filter as needed.
Best Practices for Mustard Algae
- Brush aggressively and don’t skip “hidden” areas (skimmers, behind lights, under rails, steps, toys, and vacuum hoses).
- Clean or replace filter media if it’s heavily loaded with algae and debris.
- After clearing the bloom, maintain consistent sanitizer levels and brush weekly to reduce recurrence.
Related Products
- Pool Shock (Liquid or Granular)
- Pool Algaecides (Maintenance / Preventative)
- Pool Brushes (Wall & Tile)
- Chlorine Test Kits & Test Strips
- Filter Cleaners (Cartridge / DE / Sand)
- Pool Clarifiers
Maintenance Tips
- Always confirm your pool volume so you can dose accurately.
- For algae events, keep the pump running and clean the filter more often until water is fully clear.
- Maintain balanced water chemistry (especially free chlorine, pH, and stabilizer) to reduce algae regrowth.
- Store tightly closed in a cool, dry place and keep pool chemicals separated to prevent cross-contamination.









