I have better luck with tetras in smaller groups, they never actually school anyways. When I had 9 neon tetras, I seldom saw more than 3 together in any one place in my 55. I found that 3 each was better for me. You cannot label every fish in this manor because just like people, they have individual characters. if I have a tank large enough for a flathead catfish, I should be able to keep one. Misinformation is everywhere, not just fish. 75% of the people buying cars from the dealership where I work have no idea how to use their vehicles properly but you don't see any laws prohibiting someone from buying a big SUV simply because their garage isn't large enough or they can't see over the steering wheel. A good LFS will talk to people about this, this is how they stay in business. If an LFS is just selling people fish for the purpose of selling them, they will likely not be in business long because they will end up having more unhappy customers who leave the hobby than stay. Some bettas like bowls, some like more room to swim. I have a 36 gallon with about 16 barbs but they probably only use 1/3 of the tank near the front so they will be ready when I feed. Someone else might have 8 barbs in a 45 gallon that use every inch of the tank, does this mean their fish are cramped? Does this mean I should only have a 12 gallon tank since that's all they use? If the fish are happy and healthy and the water conditions can be maintained, I don't see a problem. If the fish's tail is curved from hitting the glass, it needs a bigger tank. I have over 100 fish in my 55 gallon and they're still breeding like crazy and there are no problems at all. I never have ammonia or nitrites and my nitrates stay below 15. Kyle