Authorities raided the house Thursday and reported they found 343 full-grown plants - many of which were more than five feet tall.
Investigators also found 150 plants "in the incubation stage," according to Tasha Jamerson, spokeswoman for the Philadelphia District Attorney's Office.
More than 500 pounds of marijuana was recovered, including three large bags of cut marijuana, Jamerson said.
Nguyen had an "elaborate and dangerous electrical wiring system" to power the heat lamps needed to grow the plants, the District Attorney's Office said.
Agents from the District Attorney's Office Dangerous Drug Offenders Unit and the U.S. Drug Enforcement Agency also reported they found a system set up to use fabric softener to mask the odor of the marijuana.
Nguyen, who was being held after failing to post $1 million bail, was charged with possession with intent to distribute, risking a catastrophe, endangering the welfare of a child, and knowing and intentional possession of a controlled substance.
Nguyen's children, who slept about 15 feet from the alleged growing rooms, were at school when their father was arrested, Jamerson said.
There was no answer late Friday afternoon when a reporter knocked on Nguyen's front door.
Anderson, the neighbor, said the family was living in the house when he moved in 21/2 years ago.
"We talked a few minutes every day," Anderson said.
Nguyen talked about saving money to open a Chinese restaurant, Anderson recalled.
During the summer, the boys played in an inflatable pool on a vacant lot next to their house, he said.
As far as he knew, Anderson said, Nguyen and his family were "just average people."
Contact Robert Moran
at 215-854-5983 or firstname.lastname@example.org,
or follow on Twitter @RobertMoran215.