i have something good/interesting to report regarding the Flex Tanks for any of you thinking about acquiring these in the future....while i have already reported that the closures are not my favorite design of the tanks ( the 50 gallon size) i have to mention that all wines are aging remarkably well( 3 months now), in fact the barbera is almost outstanding right now and this is a far far cry from my carboy aged barbera of last year in which that 18 gallons required a good ten months for the acid levels, mouthfeel and smoothness to reach to a borderline acceptable taste level, in fact it beats all my previous barbera from other years for this stage of the game...i am not sure that it is simply because of the flex tank and having 40 plus gallons in it as opposed to six gallons in a carboy....but the Flex tank does allow for a small amount of micro-oxygenation and i am leaning toward it being the tanks versus the glass ( and i am a big fan of glass ) other than that, i have done nothing different in my winemaking for the barbera, zin and sangi that are in these tanks...what i am saying is that i think the tanks are advancing the development of the wine beyond that of what the glass does...i am NO scientist and my thoughts can only be taken as anecdotal...maybe the bottom will fall out in the future ...but as of now this is my experience...since aging vessel cost us all good money, i need to report my experience