Even though there are some negatives to 'hand stocking,' you may be able to catch some adult bluegill from nearby waters and put them in your pond.

Some of the negatives are:
1) Introducing a foreign substance into your pond, or a disease.
2) Not knowing how to identify certain fish, and then putting something in your pond that does not support your goals.
3) The legality of the same in your state.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."