Oh ok, I was wondering how you ended up using 16-18 cans. How much material did you have to process? I used to run through a couple different tubes so I know how some of the variables correlate. Usually you are only going to get the THC percentage out of the material. So from trim I would only expect 10-18 percent yield. The age of the material can alter your finished product too. I ran some old trim for a guy once and it didn't turn out at all, super dark and didn't have a sellable taste.
What kind of system is your grower going for?
I didn't weigh the initial material (trim). The tube is 3 by 24 inch. Sometimes 16 cans was sufficient, and one time 24 cans was needed. It was usually at 17. I looked at it as a cost benefit basis. The initial can will extract a huge amount and will need several cans just to get butane to flow out the other end. The quantity of extract will become less with each can until the point at which it doesn't make sense to continue using cans.
The grower wants a 10 lb active system with chillers instead of dry ice.
I feel that's a lot of butane for what you got out of it. It's good to weigh it before hand so you know what you're yielding. Example, if you get 10 grams out of 2 cases of butane, then you aren't profiting, just turning it into something else. I was only running 1/2 pounds of nugs, so I found using a 12" glass tube was best for me. I could see inside to make sure everything got touched and stopped after 3 cans when the butane flow started to clear. I don't think running the extra butane was worth it at 5$ each. When it was close to clearing I would just use my mouth to blow air through to push some of the remaining butane out and call it good. Not ethical but it's open loop tech lol