--
--
Good thread. yes this is a completely valid concern, I hardly see any picos that last over a year as well and I constantly look for them on the boards.
I wouldn't consider a 10 gallon a pico IMO... one good way to start verifying age is to look at coralline growth in picos, that too is as rare as a year+ life span, and frankly it usually takes the better part of a year to paint the inside of any tank purple. I have seen quick coralline in well-dosed picos, but not enough to fill up a tank within the year.
Sorry to hijack but my reefbowl was 2.5 years old at the time of filming on this link, it lived to 3 yrs before my ac crashed one day and killed it. I set up another one that is now 1.8 yrs old, it's just like this one:
http://www.youtube.com/watch?v=e3lhEeOCpao
also check out the links provided in the information portion of the vid, those are year+ as well
I think that another intersting aspect to consider is the -scaling- of these systems across the board and that relationship to larger (more commonly acceptable) reefs...scaling insofar as larger reefs need sometimes a gallon of topoff water per day, and picos need usually a shot glass, larger tanks get fist-sized frags, picos get thumb-sized...larger tanks need 50+pounds of live rock to fill out an aquascape, most picos need about 3 lbs...
the scaling I'm particularly interested in scientifically is life-span/metabolic scaling such as developing old tank syndrome (in picos that have sand beds) vs the timing of larger reefs developing OTS with the usual care methods...even though the critique exists that any pico under a year was temporary holdings, the same could be said for the vast vast majority of larger tanks that don't make it to 5 years. So, in scale, a year+ pico in my opinion is the equivalent of a 5-8 year old larger reef, still only in the top 2% of reefkeepers IMO!!