how long do i purge?

what exactly is purging. i have a pressure tank and vac. Ive got quit a bit of bho in the tank now. I think about 14 grams. Been under pressure for about 20 hours. temps were about 100 for the first 15 hours, and about 125 for the past 5 hours. ive let the air out and taken off the lid i think 2 or 3 times. other than that its been under pressure with the vac off. Still lots of bubbling going on. wen its done is it suppose to not bubble anymore at all? or will it always bubble?

i think i found my answer. i just need to keep it going another day or two until theres no more bubbles xD

ive learned alot from this guy.

I had to purge my batch for 3 or 4 days in total so it takes a wee bit.

Ive been told by peeps on here flipping the patty a few times every few hours after teh initial first pull about 12 - 24 hours in helps.

i think i need to flip it. i just scooped up a tad bit to test out,then put it back under pressure, and now theres tiny bubble where i had just scraped.