In an effort not to hijack the 3 gallon tank thread, I thought it would be best to continue this discussion in a separate thread. I know this can be a controversial topic, but at the same time, I think it is an important one and one that needs to be discussed. Both sides of this argument have valid points, and I think that a meeting of the minds can be had if all parties agree to keep it civil. (I promise.) 
Caprichoso,
Your argument seems a bit in need of refining.
First, you say that you disagree with animals being kept in zoos, yet many zoos (especially the biggest ones) have been striving over the past 30+ years to make their exhibits as true to their natural habitat as possible given the confines of the space available. Many of the animals have far larger and better kept enclosures than ever before. Certainly there are still some smaller zoos who can't afford to do this all the time, but every effort is made by the keepers to make the animals lives as rich as possible.
This idea is direct contrast to the fact that you yourself are a fishkeeper. You can try to fool yourself into thinking that you are in some way different than the zookeepers, but you have the same limits that the zoos have. Your 140 gallon tank is no different than keeping a cheetah on 2 acres of land.
Next, you are placing your thoughts on to the fish. Fish and animals in captivity if properly kept have some great advantages over those in the wild. First, the limited chance at predation. Second, the promise of food. Third, the proper environment (most of the time). Captive animals generally outlive their wild counterparts by a 2 to 1 ratio, sometimes even higher! That's not an accident. Unlike a captive animal, the wild animal will always be competing with younger, fitter rivals for food, breeding, escape, etc. The captive animal can live its life in relative peace and reassurance that all of its needs will be met.
Finally, let me say that I am not attacking you personally. I generally find your posts to be well thought out and your advice is most welcomed. But, this thought seems a bit underdeveloped. I agree that there are limits to how small is too small, but the answer to it is not as black and white as I believe you are trying to make it. We can only measure certain things in this hobby. Unfortunately, one of the things that we cannot measure is happiness or contentment of our fish. We look for signs, like coloration, breeding, activity, and the chemicals in the water that we can measure to indicate our fishes well being. I am not going to be keeping a betta in a little cup (in fact I refuse to be a patron of a store that sells them that way), but to say that 3 gallons isn't enough for a betta might be too far in the opposite direction. Bettas are not big swimmers. The same is true of ADFs. They don't need a lot of swimming space (unlike a bala shark or even a danio). These animals generally hang out in one spot or another most of the time. And if they are giving off breeding behaviors and all the other signs indicate a healthy environment, then I believe it is fine. Would bigger be better? I don't know. Too much current (for the betta) or too deep of water (for the ADF) would also be a problem.
Caprichoso,
Your argument seems a bit in need of refining.
First, you say that you disagree with animals being kept in zoos, yet many zoos (especially the biggest ones) have been striving over the past 30+ years to make their exhibits as true to their natural habitat as possible given the confines of the space available. Many of the animals have far larger and better kept enclosures than ever before. Certainly there are still some smaller zoos who can't afford to do this all the time, but every effort is made by the keepers to make the animals lives as rich as possible.
This idea is direct contrast to the fact that you yourself are a fishkeeper. You can try to fool yourself into thinking that you are in some way different than the zookeepers, but you have the same limits that the zoos have. Your 140 gallon tank is no different than keeping a cheetah on 2 acres of land.
Next, you are placing your thoughts on to the fish. Fish and animals in captivity if properly kept have some great advantages over those in the wild. First, the limited chance at predation. Second, the promise of food. Third, the proper environment (most of the time). Captive animals generally outlive their wild counterparts by a 2 to 1 ratio, sometimes even higher! That's not an accident. Unlike a captive animal, the wild animal will always be competing with younger, fitter rivals for food, breeding, escape, etc. The captive animal can live its life in relative peace and reassurance that all of its needs will be met.
Finally, let me say that I am not attacking you personally. I generally find your posts to be well thought out and your advice is most welcomed. But, this thought seems a bit underdeveloped. I agree that there are limits to how small is too small, but the answer to it is not as black and white as I believe you are trying to make it. We can only measure certain things in this hobby. Unfortunately, one of the things that we cannot measure is happiness or contentment of our fish. We look for signs, like coloration, breeding, activity, and the chemicals in the water that we can measure to indicate our fishes well being. I am not going to be keeping a betta in a little cup (in fact I refuse to be a patron of a store that sells them that way), but to say that 3 gallons isn't enough for a betta might be too far in the opposite direction. Bettas are not big swimmers. The same is true of ADFs. They don't need a lot of swimming space (unlike a bala shark or even a danio). These animals generally hang out in one spot or another most of the time. And if they are giving off breeding behaviors and all the other signs indicate a healthy environment, then I believe it is fine. Would bigger be better? I don't know. Too much current (for the betta) or too deep of water (for the ADF) would also be a problem.
You're still a good guy in my book, and have offered me with many good pieces of advice, and I hope I can count on them again in the future. 
)
