About Guillards F/2 Media

Our F/2 Media is a highly concentrated cocktail of various nutrients and salts that phytoplankton require to grow. If you want to grow your own high-quality phytoplankton at low costs, read more about our product.

The Guillard's F/2 Media we provide is a 1000x concentration, meaning just one milliliter of our potent liquid can culture one full liter of microalgae. It was originally formulated by Guillard and Ryther, who first created F media as a reliable alternative to seawater, which had varying amounts of nutrient levels making it unsuitable for algal experiments. However, F media was much too concentrated, so they popularized the F/2 media, which was the same ingredients but at half the potency to prevent toxicity and precipitation.

To use F/2 media, add it to sterile seawater at a concentration of 1mL per liter. Sometimes if the microalgae are not growing fast, you may want to add up to 3mL, but be careful not to overdo it lest toxicity may occur. Keep in a cool, dark place and use within three months so that the metals do not precipitate. Refrigeration is very helpful for preserving the vitamins in F/2 like Biotin or B12, so do try to keep it cool. NEVER FREEZE. Freezing makes it inaccessible to the phytoplankton culture.

You can purchase it here

CONCENTRATED F/2 Guillards Phytoplankton Liquid Fertilizer-50mL, Makes 50 liters | eBay