What's changed is we've gotten smarter and learned from our mistakes. Hell, getting most things to live past the year mark was considered an achievement back in the 80s. Now we're breeding corals, angels and tangs in captivity, back then if you'd have told me that, I'd have told you you were crazy. We knew damn little of the chemistry and interactions back then, the best we could do was a calcium reactor and hope for the best. We didn't have a decent venturi skimmer here in the US that anyone could afford. The Tunze units back then were $600 if memory serves me correctly, a hell of a lot of money back then. I was making $15,000/ year in the Army. We had 4 salt mixes back then, Instant Death, Marine Enterprises, Marine Environment and Hawaiian Marine. Now there are at least a dozen and people are starting to use NSW here in the US. If I didn't have the plague I'd be out collecting water this weekend. I collect 3000 litres at a time.