How to Reuse Empty Mineral Water Bottles as Betta Fish ( Betta splendens ) Tanks Materials needed - Clean empty plastic water bottle (500 ml or 1 L recommended) - Sharp scissors or utility knife - Fine sandpaper or file (optional) - Aquarium-safe silicone sealant (optional) - Small piece of sponge or foam (for filtration, optional) - Airline tubing and mini air pump (optional) - Live or artificial plants and hiding spots (e.g., small plastic plant pieces, clay pot shard) - Water conditioner (dechlorinator) - Thermometer (optional) - Heater (optional for stable warm water) - Net, clean bucket, and towel for handling Betta Fish (depositphotos.com) Step-by-step instructions A. Clean the bottle thoroughly - Rinse the bottle with warm water and mild, unscented dish soap. Rinse repeatedly until no soap residue remains. - Avoid harsh chemical cleaners that can harm fish. Do not use bleach unless rinsed extremely thoroughly and left to air out for 24+ hours. B. Choose and prepare the bottle sh...