@Byron happy fish lol. I stated this many times on this thread please respect it. this thread was an entry into a competition for tank of the month not a debate about how I stock my tank. There is a new thread if you wish to take this up please go there.
I will match my tank against your tank any day including lovegevity of my fish. I find it so funny how you think you know what makes a fish happy . I'm going to say this one time and only one time there is no science proven that a pair of tetras will not thrive in a community tank if they are not in a large group of the same fish (shoaling).
This is my hobby not yours I would not enjoy my 55 gallon tank if I only had 18 of my 24 fish bioload being two groups of tetras and a group of panda cats. I really don't like your tone I've been doing this hobby since 1970's and my fish are happy lol and usually live a very very long life with me and usually reach their Max in their life span.
I personally think what's more important in a aquarium is compatible tank mates consistent water parameters and alternating their diet. This post is not a debate this was a entry into a tank of the month competition. Please go to the other post if you want to continue this conversation yours truly Tony.
PS. I personally think people waste too much time chasing softness hardness and pH levels of their water when they should be focused on consistent parameters. For example each fish has a range of softness and hardness as well as pH however we all know that the majority of fishes are born in artificial fish hatcheries and usually are not in their natural habitat parameters. To me the most important factors 0 nitrites 0 ammonia low levels of nitrates and consistent level of pH and hardness whatever you decide to meet the needs of all the tank mates. Good day sir.