Over the course of the hatchery season, you’ll need to add nutrients to your tanks to support the growth of your seed. There are two common nutrient solutions available on the market. 

For multiple seasons, GreenWave has run side-by-side experiments adding F/2 and Provasoli Enriched Seawater (PES) to our tanks. We have found no significant differences in spool quality or the number of days until outplanting. Due to its ease of use and affordability, we now solely operate with F/2 in our hatchery and feel confident in recommending it to others.

Guillard’s F/2 Nutrient Media

If you plan to use F/2, place your order one to two months ahead of the hatchery season to be sure it will arrive on time. In the GreenWave nursery, we use a powdered form of F/2 because it is easier to mix and it has a longer shelf life than the liquid form. As a reminder if you choose to use the liquid form, you will only want to use Part A and Part B. Part C contains silica, which can support diatom growth (a common contaminant). Both solutions can be stored, unopened, in a refrigerator until the start of the season. 

For making F/2 from the powder form, add 100g of powder per liter of sterile seawater. Dose your tanks at 0.22mL per 1L of water in the tank. You can refer to the Media and Solutions Chart for easy reference.

Based on the recommendations for adding liquid F/2 to seawater, add 0.129mL of both part A and part B per liter of water in your tank. For example, in the GreenWave hatchery, our tanks are 75L which results in a nutrient addition of 9.6mL of each solution. We have chosen to round this number to 10mL of Part A and Part B for ease of operation.