Cannabutter crockpot help! cook with lid on or off??

Hi all, making my first batch of cannabutter from the trimmings of my 3 plants I harvested, also my hydro plant that just started budding had to shut down the operation for now cause I was growing in the closet and developed a mold problem on my walls lol anyway, I put 8 cups water, 2 lbs unsalted/unsweetened butter and 92 grams of trimmings that I ground up in a coffee grinder in the crock pot on low...so its coming along great so far, smells delicious as well but do I continue to cook it with the lid on or off??? Please help!!!!!!!!!!! thanks ^_^

LID ON! always keep the lid on follow this https://www.rollitup.org/cooking-cannabis/257281-make-butter-better-ultimate-recipe.html