Airsoft: What kind of BB's?

What kind off BBs should i get? regular, or biodegradable. i do have some targets in a pond i want to shoot, but i dont wnat bits of plastic floating forever in my pond. But im not sure if caring for bio bbs is worth it. What "cool and dry" areas would be best to store them. Also, if you decide reg bbs are better, what color should i get? Black or White?