Think I'll hold of on the BG and give it some time. Sounds like by stocking them things will get fairly complicated. Not sure about adding HBG either as theres no benefit to adding forage for the predators with them, but on the other hand they would be fun to catch.
Certainly can't argue with cautious approach to what sounds like a great situation already.
Adding HBG actually will expand your forage base somewhat, they will spawn, though with much less efficiency than BG. Each successive generation will have more and more characteristics of pure GSF, in my experience. That's what I meant about being able to add them without causing a major perturbation in a pond that already has GSF; your risks are pretty negligible.
