Thanks Paul...I find the history of this hobby facinating... I got in at the end of metal framed tanks, but the transformation into more "modern" fishtanks happened about 73ish and was VERY fast if you recall...
...rambling on, but....
and by sometime around 78-79 it seems Ehiems, Aquaclears and powerheads became more common...it seemed prices dropped, and SW fish had a "reasonable" survival rate (at least for mid-level hobbyist like myself) ....
Since IMO basic aquarium equipment has evolved a lil but not "revolutionarily" so,,,
...later I thought a big leap in SW tanks happened about 81ish ...seemed something happened in the Pacific region and all sorts of fish became available, although few lived very long...
...I could be wrong, but I'd say things changed again around 95ish, when Skimmers became cheaper along with Icecap ballast, et....
and just from my short hiatus I'd say we are in the mist of another paragdim shift