What is the stringy black substance in my indoor fountain?
If your fountain is in area where it receives a moderate amount of sun, algae will grow. Algae come in several varieties, but string algae are the most bothersome. They can be controlled by changing the water frequently or by adding an algaecide, such as Fountec, to the water. It requires adding only a drop or two per gallon per week. Never use bleach or similar products they will attack the gaskets of pumps and create worse problems.
