Actually aggression is not really my main concern. Here's my timeline:
June '09, I realized that the Intex pool wasn't being used anymore, I researched online and realized there were other crazy folks who used this pool as a pond. I set it up and realized that there was a very minor leak. Took a few more weeks to source tarps and finally set it up by August.
August 05, 2009: I started to dump water changes from my 100G into the pond.
August 09, 2009: I set up an improvised filtration system mixing my old media with my new media. Added some tilapia, feeders and hito. Pond is about 1/3 full at this point.
August 13, 2009: DIY 4 Level Cabinet Filtration set up. The 4 day old+new media was further mixed into the cabinet allowing BB to further multiply exponentially. On this day I added the 2' ID Shark. Might be earlier than I should have but the owner was in a rush to dispose. 2/3 full at this point.
Checked for ammonia: 0ppm. (That friggin' cabinet filtration actually works!!

)
Throughout this time, I've been adding more and more water into the pond, I have not done any water change yet. I guess I should test for Nitrates. For all intents and purposes,
my pond is not even 2 weeks old. Today, the pond is about 75-80% "full".
So my question is whether my pond is stable and mature enough for me to start throwing other fish into it. I'm generally a patient man who can exercise restraint, but if you guys start encouraging me, I'll start stocking that pond like crazy...