Update on the Mega Aerotank. I think I've figured out a decent, easy way to get rid of my gaps with the red tube. I am using it right now with no leaks, but I only filled it half way, just in case. If this works out in the long run, no o-rings are needed! (Sorry about the bad pics, I just don't have the knack!)
Here is how it looked with the stacked o-rings. The OD is perfect, but there is just the smallest gap top and bottom. It works, but still the gap bugged me.
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I was thinking and thinking of what I could use instead of the o-rings for a cleaner fit, and while filling another tank, my eyes fell on one of these little guys. (Mt. Baker needle tip caps)
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The material of the little caps for the needle tips (I'm not sure what it is made of) feels a lot like the material that the seals on the Mega are made of. It is already in contact with juice from the bottle, so I figured, why not! I cut the 'tail' off the ring and tried several different applications. Finally, I sliced the ring down the center, giving myself two rings. One UNDER the Mega's seal, around the center post, of top and bottom pieces and the tube fits perfectly!! Here is how it looks. No leaks so far, I've been vaping it for a couple of hours now. I'm pretty happy!

I think it looks fabulous!
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