After years of using S&B vaporizers I had first some problems using my Solo 3 v2. I don’t like cooling with water and the open stem of the Solo was a bit too direct and harsh to me. So I tried a cooling stem with small balls inside, the cooling was good but it gave to many draw restriction, and strange airflow for me. So I started experimenting. I found out that mixing small, medium and big balls gave me a very satisfying result. Starting with the big balls followed by mixing the medium and small balls gave a very good airflow and cooling. Easy to clean and less reclaim than with small balls. I also transformed my original stems with just adding a screen on top. Love the XL stem now. Like always this is just my humble opinion. Other ideas from you all are very welcome
Great idea, I have done this very thing as well with my old Argo stems but used one size balls. Made the vapor much less irritating. I will need to try mixing the sizes of balls to customize the stems to my liking. Next clean of my TM2 glass stems with balls will need a reassembly with a variety of sizes.
Here’s what I use:
It uses a screen instead of glass with holes in it so the air flow is really open. You just have to be careful not to outpace the heater with your draw. You can also pack it much tighter than the aroma tubes because of the open airflow.
The 2in1 means there are two different screen notches so you can use it as either standard size or xl.
I’m with you on water. I find I like dry better. I feel like water blunts the vapor too much. I may feel differently if I was doing 2000 degree ball vape rips 
Very nice looking cooling stems 
. I do something similar with the Frolic but for my S3 I always liked using the WPA with a nice j-hook.
As @Tempus mentioned, I think it’s a really good idea to move to the screened stems/WPAs available from SneakyPete and 420EDC. Maybe LaCentraleVapeur carries them since you’re in Europe? The glass screens get clogged very easily and if even one hole gets clogged, it really impacts airflow.
I also like to pre-load the WPAs, cap them with the rubber stoppers and sort of use them like capsules.
“I also like to pre-load the WPAs, cap them with the rubber stoppers and sort of use them like capsules” that’s a cool idea. J hook is looking cool but I try to keep it simple. In Europe we have less choices, for now I am good but I will look for other possibilities. The glass screens I keep open with toothpicks and I have 5 stems now, once they are all dirty I clean them all at once.
What ball sizes did you end mixing with?
I had them from other stems, difficult to measure. Roughly said 7,5mm 5mm 3mm (or 8, 6, 3mm)
I tried similar with my Go SRT, have got steel balls at hand and filled the stem completely. I think they are 3mm. After a week or so i reset to the open stem; the Airflow was not a problem but i have got the feeling that too much of the goodies condensate out of the vapour and the Vape became too weak.
But i never tried with less Balls. In the End the Vapour is okay for me. Could be colder but not for the Cost of effiency.
This is something everyone should try as you get the exact draw restriction and airflow that you desire and that makes so much difference to the experience.
I did this same thing back when I first got my TM2 and was using the stock cooling unit and the restriction just felt too tight so I opened up the cooling unit and took out the nuts and replaced with these
They are so so tiny and at first I only used 5 but then restriction felt too loose so I added more until it felt just right.
I used my TM2 like this for about a year and half and only reason stopped using it with this is the 3d cooling stem I got is just perfect airflow and restriction for me and is lots easier to clean.
See it can be hard to get a stem that is just right for you and expensive trying different stems so doing your own with your own balls and parts is something you should all have a go at.
You are right, you have to experiment till you got the result you like. And it doesn’t have to cost a lot of money, those balls I mixed I already had at home. Like you I tried with less, didn’t work but I kept on testing. For my HR rogue 2 I also use the 3D cooling stem, works perfect and easy to clean. I bought one for the solo too but the result wasn’t that good. But now I’m fine, just by playing with my balls (that sounds a bit strange no ??? 
)
I am right with y’all here. I’ve got cooling balls in all my stems now, often a mixture of sizes. Even but some in Ed’s TNT stems and they cool my TM2 like nothing else.
