Benefits of Spirulina in Aquaculture

Arthospira Platensis, or Spirulina, is a cyanobacteria that thrives in alkaline (9-11 ph) and warm water. Spirulina has been around since billions of years ago. Spirulina cells are multicellular and form helical colonies called trichomes. Spirulina trichomes are motile, meaning that they can move.

Spirulina has many things about it that make it a valuable organism. First, it contains phycocyanin, a valuable antioxidant. Phycoyanin can also be used as food coloring. In addition, Spirulina is full of other nutrients and is up to 50% protein in dry weight.

This makes Spirulina good for filter feeders and fish, as it can help promote immunity and protein fulfillment.

How to grow Spirulina

Growing Spirulina is one of the simplest endeavors in the algae cultivation community. Since it grows in very alkaline waters, it has a lower chance of contamination. Here is a simple guide on how to gow spirulina.

🧪 What You’ll Need

To make a simple DIY nutrient mix for growing Spirulina at home, start by preparing 10 liters of distilled or dechlorinated water. Into this, dissolve 20 grams of sodium bicarbonate (baking soda), 2 grams of potassium nitrate or urea (used as plant fertilizer), 0.5 grams of magnesium sulfate (commonly known as Epsom salt), and 1 gram of sea salt. Add one drop of Fertilome Chelated Iron or any aquarium-safe iron supplement to support healthy growth. For even better results, especially if growth begins to slow down, you can include trace micronutrients similar to those found in F/2 or aquaculture mixes. This blend provides a balanced base for Spirulina to thrive in home conditions.

🧂 DIY Spirulina Nutrient Recipe (Simple)

Mix into 10 liters of water:

• 20 g Sodium bicarbonate (baking soda)

• 2 g Potassium nitrate or Urea (plant fertilizer)

• 0.5 g Magnesium sulfate (Epsom salt)

• 1 g Sea salt

• 1 drop Fertilome Chelated Iron (or aquarium plant iron)

💡 Optional: Add micronutrients (trace elements, like in F/2 or aquaculture mixes) if growth slows.

🌞 Growing Conditions

ParameterIdealLight12–16 hours/dayTemperature28–35°C (82–95°F)pH9.0–10.5AerationContinuous

🌿 Daily Care

• Stir or bubble daily to keep algae suspended

• Check light and temperature

• Top off water if it evaporates

• Add nutrients weekly or after harvesting

✂️ How to Harvest

1. Pour culture through fine cloth or tea filter.

2. Rinse with clean water.

3. Scrape off Spirulina paste.

4. Eat fresh or dry on a plate in the shade.

⚠️ Warning Signs

• Yellow/clear = not enough light or nutrients

• Bad smell = contamination (start fresh)

• Foam or scum = pH too high or overgrown