Thanks Andy for that post. I like the little fish think like big fish idea. That is kind of how I've always looked at it, just never thought of it in those exactly those terms.
My understanding is that when books and websites state "minimum Tank Requirements", they mean minimum for a small fish, not the fully grown version. Thus, the "minimum" wording. With Tangs, that have immunity and stress issues that a lot of other fish don't have (or at least not to the same degree), I tend to stick within those guidelines in hopes of keeping them healthy.
I also agree that buying really small Tangs would work for a short period of time. The OP never asked would they be okay for a while, which is what my answer was based on. I've never seen the point of buying fish that are going to get too big for the tank I am putting them in, so i guess i assume, unless stated otherwise, that people mean "will it work long term?". Trying to catch them and stress them out down the road just seems odd to me. I get attached to my fish and like to keep them for the long haul.
Thanks Todd
The way I see it, if we look at the mature sizes of the average fish in our tanks then went with all the guidelines for these fish, we really shouldn't be putting almost any fish in any tank. Nano tanks would be considered cruel and unusual punishment. Keeping a single fish that is, by nature, a schooling fish, that too should be frowned upon and illegel. Probably 50% or more people keeping fish today would fit into these catagories. But... here's the thing, fish don't always read books or go to "school" to be happy and healthy. To say that a single schooling fish is unhappy when by himself doesn't really cut it ( in my book at least) when the natural act of schooling is designed for protection against predators. If there is no chance for predation in the tank, why wouldn't the single fish be happy? I say this because some schooling fish, as younger fish, become solitary or stay only with a single mate as adults. I know, this whole thing can be confusing.
Point being that I have taken very small fish and have kept them for many years before rehoming them to larger tanks. My last saltwater tank (75 gal) contained only 3 fish when I had to dismantle it for a move. 1 was an 8 year old Maculosus/ Asfur natural hybrid, 1 was a 10 year old black saddleback clown and the last was a zebra serpent star that I had for 6 years. Considering that the Angel was over 8" when I had to give him up but was only about 1" when I got him, one would have to think that that 75 was not too small to keep him for that length of time or that he was unhappy during his stay. This can be debated to death but I have no doubts about the health of my fish.
As to my little fish/ big fish thought process, I used to see this all the time, especially in groupers. When we were importing 2"-3" Bumble bee groupers (Pomacrops lancelatus) for example, we would watch them looking at 4" fish and trying to eat them. That's a mental thing not a size thing don't you think? We'd see juvenile fish act like Big Bad Terrors against larger fish and we'd think " That fish has either guts or no sense!" lol It's all just studying fish behavior.
So, in reality, considering that most people don't keep these fish for as long as their natural lives are (25 years for some clownfish for example), I think it's rather "iffy" that someone who hasn't kept a fish for it's entire full lifespan, should telling someone else what they HAVE to or should do. Obviously, this is my opinion so there's no need to start that debate here
I am just giving my experiences over 30 years of marine fish keeping on these threads. I've seen a lot and done a lot so I have a lot I can and do like to share
Thanks again