I used to have a 10 & then 20 gallon tank when I was younger. I startwed out with goldfish & eventually moved to tropical fish. I had black tetra that lasted around five or six years (got them when they were small) and had a blue gourmai for around ten yrs. I stopped having an aquarium for whatever reason I don't know. But I'm know back to having an aquarium and hoping it's successful. My last two attempts in the past nine yrs were horrible to say the least. When I was younger having an aquarium was low maintenance. Now having an aquarium is totally different. Now how have ammonia tests, nitrite tests & nitrate tests. When I was younger it was only making sure your ph was fine.