Suspended algae → algae culture in water.

Mix algae with 2% Sodium Alginate (C₆H₈O₆Na₂). Gel forms with calcium ions.

Add 0.1%-1% bPEI (branched Polyethyleneimine) for CO₂ adsorption and amine groups.
Note: Keep bPEI < 1% to avoid toxicity.

Stir well for even distribution.

Drop mixture into 1.5% CaCl₂ using syringe to form beads.

Gently stir and leave beads in CaCl₂ for 30 mins.

Rinse beads with distilled water.

Store beads in lighted container at 20–25°C.

• bPEI < 1%
• Moderate stirring only
• No UV exposure
• Maintain 20–25°C
• Avoid drying
• Light: ≥ 250 μmol/m²/s, avoid too high
• No excess CO₂
• pH 6.5–7.5

1️⃣ Mix algae with 2% Sodium Alginate
2️⃣ Add 0.1-1% bPEI and stir
3️⃣ Drop into 1.5% CaCl₂
4️⃣ Gentle stirring + 30 mins sit
5️⃣ Rinse with DI water
6️⃣ Store in lighted container (20-25°C)
⚠ bPEI < 1%, no UV, avoid drying, pH 6.5-7.5, light control, no excess CO₂