If I understand it correctly, I am GTG on a backyard range, but I need your sanity check.  I live in unincorporated Okaloosa County, all the houses in my area are on 1.1 acre lots or larger.  I have on old, unused above ground septic tank that would make a good backstop.   I would only be firing 9mm, .45 and .22 pistols.  I am on good terms with my neighbors.  Am I missing something or am I GTG?

790.15(4)b is what you seek

(4)Any person who recreationally discharges a firearm outdoors, including target shooting, in an area that the person knows or reasonably should know is primarily residential in nature and that has a residential density of one or more dwelling units per acre, commits a misdemeanor of the first degree, punishable as provided in s. 775.082 or s. 775.083. This subsection does not apply:(a)To a person lawfully defending life or property or performing official duties requiring the discharge of a firearm;
(b)If, under the circumstances, the discharge does not pose a reasonably foreseeable risk to life, safety, or property; or
(c)To a person who accidentally discharges a firearm

Suppressors will keep you and your neighbors good neighbors.

My take is you a fine, you fall outside the limitations on high density neighborhoods.

I would talk to my neighbors, invite them to shoot.

The law cited above is basically a Culpable Negligence law that is firearms specific.

It's a feel-good law that provides nothing above and beyond the already existing Culpable Negligence law.

Ignore the residential density aspect as it means nothing if you're using universal precautions and shooting in a relatively safe manner.

If you have neighbors that will hear the gun fire, I assure you, the cops will come. Just be prepared to show them what precautions you're taking to prevent the bullets from leaving your property and that should be enough.  Print off the above cited law and be prepared to point out to responding LEO's the part that basically says the entire law is meaningless if you're being safe.