I bought a 5.5 ml PHAT tank for my Helix and it works well. The only problem I have is that when you back out the carto to fill the tank, the bottom edge of the cartomizer slices the O-ring slightly and little pieces come off and float around in your tank. I'm gonna try and smooth out the carto edge with a dremel and see if it slides back in better. I've only had it for 5 refills and i'm needing to order more O-rings already. I'm also going to see if I can find them locally because I don't want to vape without it cuz it works great so far!!!
I have three Liquinators,all 3.5 w/black delrin caps. I really like mine. I had the same thing going on with the black chunks floating in my juice. Didnt know what was causing it at first. Then I bought a Mantis Mod and The EZ TANK to go with it.The first time I refilled it ...there they were..those pesky little black chunks afloat in my liquid. So I think any tank of this design could potentially make chunks on refill . When I was @ Vaporescence talking to John about these and watching him build my new one ,I noticed he swiped the cart with liquid and then slid it back together,same deal with the tube and o rings. That is the trick ..
Dont ever slide it in without some lube. I always lube my cart and orings then it doesn't seem to have the oring chunks anymore.
The Liquinator is hard to beat. It keeps that cart super wet and keeps the vapor coming. Out of three Liquinators I have had nothing but good luck. Mine are not leaking and function very well. The cart slicing chunks out of the oring is the ONLY issue I have had and I was told to lube when I bought it so I look at that as my own fault. I may try your dremel idea as well,just an insurance policy that my liquid has no chunks. Good luck with the Liquinator. I heard them say that the anodized aluminum in colors is coming out this week. I am waiting .....