Priming my Pumpkin Ale (Picture)

I fermented my pumpkin ale for a 10 days in primary and then racked to secondary for another two weeks. I used the Midwest pumpkin Ale kit and tweaked the recipe a bit the biggest change being that I used 75 Oz of canned pumpkin added in the last couple minutes of primary. It is clear that I lost a considerable amount of beer due to the pumpkin trub but I am not too sure how much.

This is my fifth batch so I am relativley new at this but my best guess would be that I lost about 1.5 gallons when I transferred to secondary. I just don't want to add too much priming sugar and end up with bottle bombs, so I was hoping that someone could advise me on how much beer I actually lost. The attached picture is my beer sitting in my 6.5 gallon glass carboy atop the massive amount of trub. Any help would be appreciated in determining how much I lost and how much dextrose I should prime with ( I was thinking about 3.5 ounces).

Thanks

Yeah that sounds good and safe.

Alright thanks Revvy looks like that's what I'll be going with.

How did the carbonation turn out with that? Seems a little on the low end.

At almost three weeks in the bottle they are carbed up quite well . I would add maybe another .25 oz next time but its still early and they may turn out perfect after another week or so. They have about a half inch of head which is not quite as much as I would like but may increase over time. Have drank a couple myself and have given some to friends and gotten good reviews. Cheers!