So, you know how plants need food to grow? Well, algae also need food to grow, just like plants! But instead of getting their food from the dirt, algae get their food from water.
But not just any water will work - algae need a special kind of water called "algal nutrient solution." Think of it like a special recipe for food that only algae can eat.
This special nutrient solution has things like nitrogen, phosphorus, and potassium, which are all important for algae growth. It also has some other important things like trace elements and vitamins, kind of like when you take vitamins to stay healthy.
So basically, algal nutrient solutions are like food for algae, and they help the algae grow big and strong!