Hi, welcome.
This is something of a FAQ, so you'll find further reading with a quick search:
forum.dmt-nexus.me
We have no idea how concentrated your caapi extract is, nor how it was made, so you'd best check up on that. A common figure seems to be 30:1, meaning it's likely to be the equivalent of 7.5 grams of plant material, which doesn't sound like very much. If it's a more selective alkaloidal extract 250mg would be quite noticeable.
How are you planning to consume the DMT? What kind of device will you be using? Have you tried DMT before?