What happens next?

How to grow spirulina at home
Get a tank.
Most home growers find that a standard size aquarium is perfectly adequate as a space to grow spirulina in. A tank that size will supply a family of four with plenty of spirulina.
You can grow spirulina in larger tanks, or even in a basin or pool outdoors (if you live in a warm climate). However, it will be easier to manage the spirulina culture indoors in a small tank.