Back to: Seeding

Now that you have an idea of how many spores you have swimming around in your spore solution, you must calculate what volume of spore solution you’ll need to introduce to each of your spools. There is an equation that can help you determine this volume, and it takes into account four numbers. We have created a tool to streamline the math for you, but it is still important to understand where each of the numbers come from. 

Stocking density of each spool 

This is a value that you choose. The recommended stocking density for sugar kelp is 1,000-10,000 spores/mL—which is a large range! It’s good to experiment with different values to see what works well for your operation. High stocking densities may result in increased competition (for nutrients, light, etc.) and possibly result in slower growth during both hatchery and farming seasons. A downside to low stocking densities is that it may result in lower yields on the farm.    

GreenWave Tip

At GreenWave, we typically stay towards the lower end of this range (2,000-5,000 spores/mL), usually around 2,500 spores/mL. This works well for our sugar kelp hatchery operations and success on the farm.

The number of spores in 1mL of spore solution 

The next number used in the calculation is the number of spores in 1mL of spore solution. This is a value that you calculated by multiplying the number of spores you counted on the hemocytometer by 10,000. 

The volume of your inoculation container

The third value you will need is the volume of the container you are using for inoculation. There are several strategies for inoculation containers, but in the GreenWave hatchery, we either seed our spools in seeding tubes or directly in their culture tanks. Seeding tubes are made from 4” PVC pipe cut into 15” lengths. These tubes will hold just about three liters of water. We use 20-gallon culture tanks, which is the equivalent volume to about 75 liters. To use the equation, these values must be in milliliters, so depending on the seeding method, we will enter 3,000 or 75,000 mL. There are some pros and cons to each of these seeding methods (in tubes or in tanks), which we’ll review in the next section.

Total volume of your spore solution

And finally, you’ll need to know the total volume of your spore solution, which you already took note of when you strained your spore solution. If you’re using a beaker or graduated cylinder, read the volume level.

When you have all of these numbers, you can determine how many milliliters of spore solution you’ll need to introduce to each of your spools to achieve the desired spore density. 

The spore density calculator will help with this math and allow you to make quick decisions while seeding. Simply enter your values to determine how many spools to prep for receiving spore solution, or make quick adjustments in your stocking density to help you reach your goals for the day. 

Once you know the volume of solution each spool will need, you can divide the total volume of spore solution you have by that value to determine how many spools you can seed for the day. 

These steps for managing the spore release and seeding your spools are outlined in the Spool Seeding Protocol.