We have recently gotten my son a 3.5 gallon tank. We have 1 male half moon Beta, 1 red wag Platy, 1 albino cory cat, and 1 "mixed fruit" tetra. When I received these fish I knew nothing about aquariums. Since then I have done some research and have found that I literally knew NOTHING. I did not treat, condition, test anything. I used room temp. bottled water to start the tank and let it cycle for 24 hours per tank instructions. Now I have gotten the test strips and found that the tank is a little on the alkaline side. I have also found that the mixed fruit tetra was probably given the green color by injection or dipping and that it along with the red wag and cory cat are schooling fish. My questions are is this tank too small for these four fish? What do I need to do to ensure the proper environment and their health? They all seem to be getting along and living just fine, but I want to make sure as they grow that they continue to live stress-free, peaceful, happy lives. I did not realize how great and rewarding having a fish tank in my home could be. Thank you in advance for any and all information, knowledge, or help towards my newly acquired hobby.