I need help! I have a tank the measures 30inches across, 18 inches up and 12 deep. I have had fish in my tank since April this year. So far I have 3 Corydoras, 5 Male Guppies and 2 Ghost shrimp. I have sand substrait and plastic plants and things for fish to hide. Having troubles figuring out what other fish to put in there and how many of each to do... I have been looking around the net a lot lately and web site say opposite things... its confusing! I had a group of 6 neons but they died.. so I tried again and they died too... not sure if it is the hardness of my water or the location I got the fish. But my other fish are doing great. I add water to the tank every week cause it evaporates out quickly and I have a Tetra Whisper 40i filteration system. My hood is a LED with white and blue lights, and I have a bubbling system... LOL this is my first tank. I would like a community tank with a center piece fish but afraid of over stocking my tank. I had male and female guppies but didn't research them as much as I should of and didn't realize they are rabbits of fish world. lol But all the babies found happy homes. Please help me I want to do this right.