Despite a sophisticated filtration system, it was the smell that smoked out a marijuana-growing operation located just 25 feet from the LAPD’s Topanga station in Canoga Park. LAPD officials said officers began noticing the smell of marijuana Tuesday morning. They investigated, got warrants and closed down the indoor farm within eight hours. Three men were taken into custody earlier Wednesday after officers served a search warrant on the warehouse in the 8400 block of Canoga Avenue. “The growers had built three rooms in the building; one for seedlings, another for medium-sized plants, and one where harvesting was apparently conducted,” police said. The lights were controlled so they wouldn't overheat, watering systems were automated, and oxygen levels were supplemented by carbon dioxide tanks. "It was very sophisticated," said LAPD Officer Karen Raynor. She said growers used insulation material to seal cracks in the building. But about a week ago, officers in the station's parking lot noticed something out of the ordinary."They happened to catch a whiff of it," Raynor said. A surveillance operation was launched, and officers obtained the warrant. The names of the three men, appearing to be in their 30s, were not released because they had not been booked.