The toptanks lose their vacuum when opening the topcap, when used with high pg-juice it could cause leaking issues through larger holes, that's probably why they narrowed down the juiceholes on this tank. Maybe there were complaints about leaking issues of the STM RBA too, we might never know. You can still get RBA clones with the original sized (bigger) holes though.
When you have leaking issues maybe you need to replace some o-rings or use more wick.
Due to the limited airflow, space of the builddeck and limited juiceflow i never managed to use very low-Ohm coils or too much Wattage. Somewhere around 0.4 Ohm and 25-30 Watt is pretty much as low and high as i can go on a Subtank or Toptank.
THANK YOU SO MUCH for your timely reply! Interesting you mention the orings as that thought occurred to me almost immediately after I posted my question. Due to the fact the leaking has been from the bottom of the tank, (adjustable air flow holes), I went ahead and removed the hardware & took out the oring to see if I could find any nicks or damaged areas. I also figured a quick cleaning couldn't hurt anything. I had never replaced the orings & thought there was a good chance it had some "wear & tear". I didn't locate anything damaged but of course there was a small amount or traces of dried juice that had accumulated under the oring so I cleaned it out real good & put the old oring back in & filled the tank. I guess I need to check the top one as well? I assume it would have an impact on any pressure issues that could be taking place?
As far as juice goes, I am having the issues no matter what juice I put in the tank. Some of what I like in that particular tank is the same juice I've always vaped, even before the leaking began. Or perhaps I had some before but never even noticed. If so, it was nowhere near what it is now. When you say high pg, how high are you talking about? I don't consider any of my juice high pg, but perhaps I'm idea of high pg is not accurate. If available, I tend to go high vg as I learned that for me, a thicker juice is better due to the way I vape, or the "hits" I like to take. I have also upgrade hardware a few times since I began vaping & therefore have compensated for that by increasing the strength of vg in my juices. If I were to use high pg, I would burn up my coils immediately. Please feel free to correct me if ANYTHING I'm saying is not accurate as I know I'm far from a vaping expert. lol To give you an idea of my idea of high pg/vg juices, I will not purchase anything greater than 50/50. I try to get something closer to 60/40, at the very minimum, if possible, and I'll go all the way up to 100% vg. HOWEVER, that isn't what I put in my toptank or subtank mini's. That would go in one of my crowns. I will say this, the leaking tends to be much worse when the juice gets hot. For instance, when I leave my device in my car too long. This made perfect since to me as the liquid thins out as the temp rises, so I try to be mindful of where/how long, it's left in the heat.
And lastly, one other thing I did yesterday immediately following my post was diagnose the inside of my coil. I just replaced it but it appeared there was a very small, really small, area where I thought it might could use some additional wicking. Now remember, I do not build my own coils so this was strictly speculation on my part but thought what the hell, I have nothing to lose, so I cut a tiny piece of cotton (yes, I used cotton from the rda kit that comes inside the Kangertech tank box), & filled in that small area. I had no idea if it would actually make a difference, fall right out, or what might happen, but I was willing to take the risks. So far, so good. I haven't used that take a whole lot since my post as I was kinda waiting to see if I would get any replies....Low & behold, you came through, & I'm extremely grateful for that. So again, many thanks for all your info, & help with my MANY questions. I truly appreciate your time as I'm certain you have much more fun & exciting things to do w your time.
Cheers,
Becky