Ornaments add appeal to your fish tank, but when algae builds up on them because of excess nutrients or waste in the water, it can ruin the appearance of your fish tank. Algae usually appears as a green or brown film that develops on the ornaments, tank or in the water. A mild bleach solution can dissolve the algae residue and won't disturb the water composition if the ornaments are rinsed well. Clean your fish tank and ornaments and change the water periodically to prevent future algae growth.
Remove the ornaments from the fish tank.
Fill a clean bucket with 1 gallon of warm water and add 1/2 cup of bleach. Place the ornaments into the bucket and allow them to soak for 15 to 20 minutes.
Scrub the ornaments with a scrub brush to remove all traces of dirt or algae.
Rinse the ornaments thoroughly with clean water until no chlorine smell is detected.
Set the ornaments in a well-ventilated area to air-dry completely before placing them in the fish tank.
The best time to clean fish tank ornaments is when you clean the tank. Make sure to use dechlorinator tablets in the fish tank water to remove all traces of chlorine after cleaning.