Guillard's F/2 Phytoplankton Growth Medium "Phyto Feed"

Guillard’s f/2 Medium – Pure Formula (250 ml)

What it is:

Guillard’s f/2 is the benchmark nutrient medium for marine microalgae culture, originally formulated by Robert Guillard and still used in laboratories worldwide. Our product is the true f/2 recipe — not a modified or altered version — providing the exact balance of macronutrients, trace elements, and vitamins needed for consistent, healthy algal growth.

Why we like it:

Many products on the market claim to be “modified f/2,” but that often means reduced nutrient levels or cheaper substitutes. We use and supply only pure f/2 because it performs exactly as intended — delivering dense, stable cultures of Nannochloropsis, Tetraselmis, Isochrysis, and other marine phytoplankton species. It’s the same formulation we use in our own systems at The Happy Reef, ensuring reliability and laboratory-grade results for both home and commercial use.

Use Guide:

• Use 1 ml of Guillard’s f/2 per litre of prepared saltwater culture medium.
• Aerate and illuminate as normal for your chosen phytoplankton species.
• Maintain salinity between 1.018 – 1.022 SG for optimal growth.
• Store sealed, away from direct light, and refrigerate after opening.
• 250 ml pouch treats approximately 250 L of culture water.

Details:

• Genuine Guillard’s f/2 — pure, unmodified formulation
• Ready to use for all common marine phytoplankton species
• Supports fast, nutrient-rich algal growth
• Suitable for Nannochloropsis, Tetraselmis, Isochrysis, and Chaetoceros
• Supplied in 250 ml resealable pouch