Hey y’all so I packed the bottom of my material column with some B-80 and a couple coffee filters and the pour out was very foam like. I let purge for the night and now it is like a stable very crumble like consistently. Maybe I got some clay in the product?

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Coffee filters are 15 micron at best. I’d wager you got media in your product.


if coffee filters were your smallest level of filtration, yeah you more than likely got some powder in there. You can dissolve some of it in ethanol and warm it, if there are powders they will be visible and won’t dissolve. That will let you for sure if you had any powders slip by.


Coffee filters can be used effectively but it’s tough to stop the small clay particles completely when using coffee filter alone.

You need to manage the pressure carefully. Adding a very thick layer of sand directly on top of your coffee filter will help evenly distribute the pressure being applied to the coffee filter and should keep blowouts to a minimum. Clay should be packed on top of the sand, sand will act as a depth filter and keep most of the clay from getting into the final product.

If your still having trouble and are unwilling to buy filtration equipment, let the product sit dissolved in solvent and allow the particles to drop to the bottom of the solution and decant or siphon off the solvent to remove all solid particles. Clay will facilitate the sedimentation so it wont take more than a few hours.


Some CRC pour offs foam up really bad even if you pour slow and correctly. Wet pouring helps sometimes. While I do bet you have bentonite material in your slab, I think you can calm the crumble consistency by melting the slab down and then starting the cure again. If it’s purged sufficiently you can try to knock it down with a heat gun, if not a hot pad or oven should work too. Once it’s melted and stable you might be able to see media in there.

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I just dont know what to say about this. @ScoobyDoobie and @clouds answered this. But im not understanding why in the world would someone thing coffee filters are sufficient filters. Hell they went before powders


This is what happens when you dont read the instructions.


customgrow would be having fits lol


I see it like this, sand will get you down to 5 micron filtration and the coffee filter will be sufficient to hold the sand in place. It will work, just not to acceptable levels of any professional lab.

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That might work, idk never tried it.

If your CRC’n without 1 micron filter stacks you’re going to have a bad time

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2.5 un was sufficient for me, last inline


A big factor is how you prepare your column. What I like to do is wet set my bentonite cake by suspending my clay in solvent and then I pour it onto the sand filter while a vacuum is being applied from beneath the column. Once a decent layer of mud builds up on the surface of the sand it begins to act as it’s own filter. Whatever clay runs through the sand initially is poured back over the cake once it’s set in place and nothing makes it back through the second time around.

It’s a good idea to add more sand on top of this bentonite cake so it doesn’t get fucked up by incoming solvent, I even to go a step further and add stainless steel ball bearings on top of the sand. I like to use a 16" long 1.5" triclamp spool for my crc and a simple. This way if the cake does manage to get fucked up on top it still has a huge length of bentonite that it’s still going to be able to travel through properly before exiting the column.

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If you’re only using coffee filters, you’ve got media in the finished product


I agree with @BG305

This is the byproduct of people ignoring all the tek.

So here’s your spoon @Davepop



No offense. But its people like you that give crc a bad rep. Do it right or not at all. Theres literally a 8000 post thread about crc. And you used coffee filters




He really only has to read the first 3-4k and he’s good. Along with the last 1-200 for the latest development. Everyone has to remember that we are inherently a lazy species. We would much rather grab the low hanging fruit than climb the tree.