But, he said: "All in all, I think it will be better."
Stone announced the new policy in May after considering it for years. He said he was motivated to make the change as studies began to link more health problems to secondhand smoke.
The state Department of Corrections has also been encouraging jails to go smoke-free lately to avoid inmate lawsuits over smoke exposure.
According to the American Lung Association, secondhand smoke contains hundreds of toxic chemicals and can cause a range of negative health effects such as cancer and asthma.
It also leads to more than 49,000 lung cancer and heart disease deaths each year for non-smokers in the United states, according to the association.
Not only does cigarette smoke permeate through the entire jail due to a circulation air system, it settles on the walls and triggers the fire alarms.
Stone said crews must use special chemicals on the jail walls about every three months to scrub the nicotine residue off.
"If they smoke all day long and at night in there, it creates a lot of smoke," he said. "It creates a real big nuisance."
The Clark County Detention Center is far from alone in its efforts.
Of all the counties that surround Clark, four already ban smoking or are implementing a similar policy soon. Only two nearby jails, in Estill and Bourbon counties, still allow inmates to smoke inside.
Stone acknowledged that the jails commissary fund does about $40,000 in cigarette sales each year. But he said other smoke-free jails have reported that smoking bans have not hurt their commissary funds.
Stone also said he doesn't expect inmates to just go cold turkey.
The jail is preparing to sell more nicotine patches and other addiction-breaking aids in the commissary. Inmates will also be allowed to smoke while serving on work detail as long as they don't bring cigarettes back to the jail.
"We will try to assist them in the best way that we can," Stone said.
Prisoners are already forbidden to smoke during outside recreation, and that policy will continue. That's because jail officials don't want the recreation area littered with cigarette butts.
Employees also will be required to step outside if they want to light up.
Allen, who is serving time on drug charges, started trying to cut back anyway after participating in a substance abuse program. He said he was encouraged by studies showing that people who quit smoking are less likely to return to old drug habits.
"I think it's going to be healthier for everybody," he said.
Another inmate, Bryan Greene, is one of the few prisoners who doesn't smoke. He's glad to see the ban.
"It's OK with me," he said. "It burns my eyes when those guys smoke. I like to see them happy, because when they're happy, I'm happy."
Stone said he hasn't received many formal complaints from inmates on the matter yet. Employees are a different story.
"I don't like it, not at all," said Deputy Jailer Earl Mitchell. He has smoked for 30 years and is up to three packs a day. But Mitchell acknowledged some advantages to the ban.
"It's probably going to do us all good, to be honest," he said.