A spirulina algae kit is available, but you can also build your own. To cultivate it in a fish tank, you'll need water (preferably dechlorinated), a starter culture for Spirulina, a few of small instruments for stirring and harvesting the algae during harvest time,A sunny window or grow lights are ideal places to place the tank. Algae, like natural plants, require light to thrive. Next, make sure that the water or growing medium has a pH of 8 or 8 5 before you begin. To evaluate the water's acidity or alkalinity, use inexpensive litmus paper and add vinegar or baking soda. Stir the spirulina starter culture into the hot water when it's ready. Spirulina can be purchased online, but if you know someone who grows their own, take a tiny bit to use as a starting point. Keep the water between 55 and 100 degrees Fahrenheit at all times (13-37 C). Keep the water level the same by adding water as needed.Waiting till the water pH reaches ten before harvesting Spirulina Plant is ...