Using Magnesium Oxide

So simple question here, I was told I could use Magnesium Oxide (MgO) to make water clear disty. Also I’d have to do a constant run and no stopping to switch Flasks or then it would go the other way and produce colors. How many have used MgO for this?

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@Concentrated_humbold has spoke about using mgo for decarb I believe.

I haven’t heard about using it in the flask. Correct me if I’m wrong, but anyone making water clear on here used it as a filter pre-distillation, not during.


I messed with mgo a lil bit for decarbing, but didnt get too into it since doing it in the roto and terp stripping at the same time was efficient enough for me. So i can speak about it efficiency or for making water clear with it in the flask. @Photon_noir would be the one to ask for the best and most accurate detailed explanations


Glad to hear folks finally looking into MgO more seriously… it’s neat stuff, for sure! :blush:


I tried exactly once to evaluate how useful MgO would be for decarbing under 100C so I could avoid switching the roto bath to oil for decarb. I didn’t design or execute the experiment well and it’s one of my biggest regrets in the last 12 months lol. I wish I had learned @cdpchem’s bromocresol green trick at the time for sure: Tricks of the trade - #655 by CdpIchem

I did discover through substantial experimentation since then that eliminating any oxygen and sealing the decarb environment is very effective for not reacting terpenes during decarb into oxides and such, probably more so than lowering decarb temp by 20 degrees. I would still like to add a catalyst to the equation to further preserve the profile without needing to separate the volatiles from the cannabinoids, especially since I like concentrates with high minors concentrations.

All that being said, I’m not sure I understand the application for getting “water clear” other than maybe to neutralize the micelle to prevent the red oxidation/reaction that seems to happen. Should also note I avoid distillation like the plague so maybe not a good authority here


Had a weird experience with MgO once, the distillate (first passed and scrubbed) stayed quite alkaline and turned purple during solvent recovery.

Once it was transferred to the short path it turned clear as I was ramping up temperature, I had a terrible vac leak as soon as I hit my target distillation temps, oxygen flowed into the system and I watched the distillate turn from clear to deep purple immediately.

My assumption, after looking through my lab notes is that I didn’t adequately neutralize the scrubbed distillate and the alkaline conditions (being the last step before a single neutral wash) are what modulated color…meaning that during distillation the MgO was again the primary factor in the color change.

I dunno though, it’s mainly conjecture and anecdotal experience


Mag ox will cause conversions if you put it in your boiling flask.


The MGO to water clear post on the site was via a filter column from a first to second pass distillate. It was high d9 if I recall correctly.

I was told that as long as oxygen was absent from the system that it would help with water clear, maybe by neutralization of ph… Idk… Never heard that it can cause conversions though.

I know it can be used to neutralize acid but what would it convert to if in the boiling flask. Let’s say if mixed with CBD