No chemicals are used in its function making it safe for fish. This fogger uses no chemicals, making it safe for fish and other aquatic life. LED lights switch colors every few seconds, giving the fogger an added fun effect. Place your fogger into a floating ring, so it stays out of site while making your pond come alive with multi colored fog. This water fogger uses the water from your pond or large water body to create a beautiful fog, without heating the water or making it unsafe for fish.