Vet Q & ADoes my slider turtle need UVB light even if tank is by a window?
This will not provide sufficient levels of UVB lighting. The window and tank glass will block a large majority of the sun's beneficial rays. A UVB light source must not be blocked by glass, plexiglass or fine mesh and should be about 12-16 inches from the surface of the basking area for maximum effect. Without UVB lighting, a turtle cannot properly synthesize adequate levels of Vitamin D3, which is necessary in the absorption and metabolism of calcium. The result will be metabolic bone disease, soft shell and/or stunted growth.
Updated on September 24th, 2025