A Maricopa County judge ruled last week that medical cannabis extracts are legal. This week, County Attorney Bill Montgomery asked the judge how much extract qualified patients can possess.

In Arizona, cardholders are allowed to have 2.5 ounces of medical marijuana. The law doesn't mention extracts, like creams or oils. Montgomery wants to know whether the ruling means patients can have 2.5 ounces of extract, or the extract produced from 2.5 ounces of plant matter.

David Grandon is with Harvest of Tempe. The dispensary carries marijuana, as well as edible products and extracts.

"We do have CBD-only oil, meaning it has no THC whatsoever in it," Grandon said. That was the oil in question in the recent case. It doesn't get you high, but supporters say it has medicinal effects. "We have 100 milligram vials, 250 milligrams, and 500 milligrams."

How much cannabis does it take to produce that vial? Harvest's Eric Guru says to make 500 milligrams of CBD oil, "you're looking at over 100 grams."

That's more cannabis than the law currently allows a single patient to have. To produce the smaller bottles, you would start with a legal amount.

And, if the judge says patients can possess 2.5 ounces of extract, a single patient could legally have nearly 150 of the larger bottles of oil.