They're located at the very top underneath where you buy plasmid slots. You can also only buy a maximum of twelve tonic slots throughout the. Tonics are so varied that it's pretty much. You can also only buy a maximum of twelve tonic slots throughout the game. . The price does not change during the game. Comprar los 3: $00$ Comprados juntos In Bioshock 2, you have numerous tonic slots/plasmid slots, etc. Plasmid Slots are purchased at Gatherer's Garden machines throughout Rapture for ADAM each. Click to expand then you are able to buy. The 2nd area - Neptunes Bounty has a Gatherer's Garden where you can buy an extra plasmid slot. You can buy either of two kinds of ability slots -- plasmid (special power) or tonic (passive ability) --that allow you to use many talents simultaneously. You should be able to purchase it at the second gatherers garden:) Upvote. That's at least 4 plasmid slots, since you start with 2 you'll need to buy at least 2 more. They're located at the very top underneath where you buy plasmid slots. If you don't. extra objectives and it took me at least 25 hours.