Re: Tonics, Potions and Grenades

At the start of the game you have 1 belt slot for either potions, tonics or grenades. You can put any of those 3 in the "potion" slot. You can unlock one more belt slot through inquisition perks, but you will still be able to use any of the potion/tonic/grenade in the extra slot. You can now just use 2 different items (meaning you can't have antivan fire i both slots for instance).

Healing potions are a shared party resource, but those belt slots are individual and can hold any potion/tonic/grenade you can craft.