Hey Dave, nice tube!
I'm trying to get an idea of how big a tube's gotta be for a given number of user days. The Eco Safe units are rated at 20, and 50 user-days each, at 2.3 gal and 5.5 gal. That puts one user day at between .11 and .115 gal. 113 cu in / .11 gal = 4.45 user days. That seems really low, though. I feel like I could get, I dunno, maybe twice that into that tube. Even supposing you get 60 user days into a normal groover (which is about what I've maxed those things out at.), that's still only .09 gal/user-day, which leaves your 113 cu in at 5.3 user days.
Anyway, I'm just trying to figure out what I'm missing, or if these calculations jibe with what everybody't thinking for a tube like this. We used a tube slightly larger than this one for a 5 day wall climb for 3. We didn't use it every day, somehow, and it was FULL at the top. What do you all think?