Where buy the Grow lights?

At a news conference Wednesday, San Francisco Fire Schultneis said growers rewire the homes to avoid detection of the huge spike in energy use needed to grow pot. Shoddy electrical work can spark blazes she said, as can hot grow lights used to simulate sunshine.

Houses in the Sunset often share common walls, which allows fires to spread quickly. Growers often nail plywood to the insides of windows to keep out natural light and prying eyes, investigators said. As a result, fires can burn longer without being noticed.

City firefighters typically battle two blazes a year caused by marijuana growing operations, Schultneis said. This year they have already fought four, including one at a warehouse that onto a firefighter, causing serious samurai swords injuries.