[header] How to clean aquarium decorations [title] Remove decorations one at a time. [step] You may be in a hurry to get your tank looking fresh, but never clean all of your decorations at once. Decorations are home to helpful bacteria that keep your fish healthy. 
Removing them all at once can upset the balance of your aquarium. [substeps] Removing all of the decorations at once is stressful for your fish, too.