Here is some actual record data:
"Anecdotal evidence in several scientific reports suggest that an alligator gar can grow up to 10 ft (3.0 m) in length and weigh as much as 300 lb (140 kg); however in 2011 the largest alligator gar ever caught and officially recorded was 8 ft 5 1⁄4 in (2.572 m) long, weighed 327 lb (148 kg), and was 47 in (120 cm) around the girth."
Do you think you can provide a good care for it indoor? Your house big enough to have space to built indoor pond 20x40 feet at minimum size? Will you willing to spend around 500,000+ dollars to modifying your house so you can house a fish? IF YOU CAN THEN GO AHEAD IF NOT just keep that fish in your DREAM.
This is my first post on this message board, why are you being such an a hole? Im sure that in the fish world i am not the first person to have a gar. What did i do to you?
I'm going to guess it will take quite sometime to reach those kind of proportions. You could probably house it in a large tank for a couple years, but ultimately I can't imagine anything less than a large pond would work long term.
im surprised the guy at the fish store would stock and sell an alligator gar. I'm sure someone on here would buy it from you once it gets to a larger size