School me on running a co2 assist on a passive cls please

As I was contemplating spending the money for a nitrogen assist I walked into my grow room and realized I have a co2 tank with a regulator and even the adapter to change the regulator from 1/8" barbed to 1/4" JIC already.

I’ve heard of people using CO2 instead of nitrogen, can you enlighten me about the differences in potential effects on end product compared to using nitrogen? Will there be any visible indicator that I have purged off all the co2 once it’s assist is completed prior to solvent recovery? I run a dewaxing sleeve so if there is any moisture will it just get trapped within the column?


Co2 has tons more pressure don’t it

Are ur concerns bc some is left?

Most ppl mess up w dewax instructions if not nitro assured

To do passive right and get all u stage cold to colder…

Column dry ice only…collection in denatured alcohol/ or acetone and dry ice
I like denatured for seal not getting ate
It’ll pull the solvent through better

Also I like using warm tank w chiller coil at about -20f …then dry ice for column and dry ice denatured for collection…gives nice stage in temp

If ur column colder than collection ur getting vapor lock

Cold to colder

Sorry if I got off topic just looking for the “root” problem that got u looking for assist

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you could push with co2, I use n2 gas. You want to use it to push on the headspace of the tank to move the liquid up the diptube. You will want a good two stage regulator for your gas bottle. Start low with 20 psi and increase until you get good results. Set the regulator and throttle the inlet of gas with the solvent tank valve.We use 60 psi preloaded in our tank headspace.After injection chill the entire system to get any residual butaine gas to liquidize, burp the system and chilled tank back to 0 psi. After burping, heat the system and recover like normal to a chilled tank. If you leave the gas in the extractor during recovery it will take hours to recover your gas. We dont use co2 beacuse our systems recycle assist gas all day. We had issues with co2 forming liquid in our tanks. After the chillers were shut down and tanks were burped to 0 psi -85c the pressures would skyrocket. Usually I see about 40 psi in a warm tank of just n butaine, these were going well over 120 psi and popping the relief valves after shutdown. They key is to chill anything containing solvent to remove the gas after injection. It will speed your recovery, and won’t waste gas.phpAsNMSr as you can see, in a passive hybrid system co2 can form as a liquid quite easly.


Man. Sounds like something I’d say word for word. Hmmmm. :stuck_out_tongue_winking_eye:. Only messing wit ya man. Couldn’t have said it better.


I’ve had vapor lock occur when I attempt to chill my solvent so I figured this would help. I also dislike that I can see the material column keeps dripping for an extended period of time while recovering so I have to either close it off or let butane that soaked much longer than the rest enter into my recovery pot.

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Man @Soxhlet you’re really making me want to try using nitrogen in my Master Vapor Pump diaphragm chamber now.

Yes but I still feel like you’re missing the major reason you’re getting vapor lock, make sure you stage you’re solvent cold, your material column colder, and your collection pot the coldest…

Just this is what I was trying to say, do you stage the cold right, the remaining solvent you have trap as a vapor in your material column is colder than your collection, collection needs to be the coldest , it would draw down those Vapors turn them into a liquid state pulling into the bottom of the collection pot

U move solvent warm to cold when running passive

I was thinking the same thing , was wanting Nitto…so I started staging my cold and giving my column a slight Shake and even my lines to build a little pressure to pull with

Thanks to help from ppl here I didn’t need to Buy anything else had everytime I needed already…juat has to be dialed in

The smallest vapor ok but it shouldn’t puke after

Btw thanks to great minds here I wss taught all these "tricks of the trade "

*Turn those vapors back to a liquid


Will the compressor on the mvp play nice with a gas that light?

you are completely right. I’ve been skipping a dry ice slurry on the recovery pot. I just don’t like using iso or acetone in this process it needs a lot and the stuff stinks. If I can just push the solvent around in liquid forum with a tank i have sitting here it seemed like it could fix the problem.

Yeah I don’t like using them either I use denatured alcohol w dry ice :slight_smile:
Dry ice would work probably but take forever

Use just n butane it’s only 32f

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