Medical marijuana

This is a complex, still-evolving issue. Part of the complexity comes from the fact that even if FL allows medical marijuana, marijuana is still a CDS or controlled dangerous subtance--an illegal drug--under federal law.
It is clear that you could be fired for using medical marijuana at work: since marijuana is illegal under federal law, an employer could terminate you for having an illegal drug in the workplace.
It is clear that you could be terminated if you are impaired at work due to the medical marijuana: employers may terminate employees who are under the influence of a substance, even legal ones (e.g. alcohol; being drunk at work)  because they are not required to accept the liabiity risks or loss of productivity that come from impaired employees.
And it is clear that certain jobs can ban the use of any drugs that can affect reflexes or judgment--e.g. being a delivery driver or heavy machiner operator--even if you are not impaired at the time of doing the job; having any positive result for a drug can result in termination if you have a job where it is simply not safe to have any quantity or concentration in your bloodstream.
What is NOT clear: what if you are not impaired at work, not using marijuana at work, and not in a job where you can't take any drugs that might have any effect on reflexes or judgment, but you test positive during a random, etc. drug test or the employer otherwise becomes aware of your use--can you be fired then? In FL, it is unclear: the law authorizing medical marijuana does not protect you from firing, BUT federal law requires a "reasonable accommodation" for an employee medical condition, which would include for the employee taking medication (so long as it is not the situations of onsite use or impairment, or a particularly sensitive job, discussed above). Firing someone for using medical marijuana when it is not affecting work could be illegal disabilty based discrimination (effectively discriminating against the employee due to the underlying medical condition leading to the prescription). So a good argument can be made that it would be illegal to fire for medical marijuana use that does not impact the job, but we can't say that you would be safe: the issue has not been 100% decided, and it is possible you could be terminated even in this case.