What's the maximum time marijuana shows in a urine test disregarding weight amount smoked or metabolism is 6 months enough to give a 0.00ng/ml results?

Not guaranteed: Zero is not guaranteed if you insist on not taking amount, frequency and length of time using - not to mention other factors like weight and metabolism. I've heard of over two years for long standing heavy users. A minimal to moderate user of average description might be clear in 6 months. But no guarantees! Vote for decriminalization or legalization or move to Colorado. Good luck.

Depends on: usage and body metabolism. Heavy users can be detected months later. Less frequent and small dose users may be non detected in 7 to 14 days