About 10 years I purchased a 55gal aquarium from a pet store. I had no clue about cycling my tank and went out the next day and bought 3 Oscars and 2 Red Devil Cichlids. Within a week I lost 3 out of the 5 fish. I was devastated and thought I was doing everything right when I was doing everything wrong. I ended up giving up and giving the tank away a couple of months later after killing all of the fish. I recently bought a 120gal tank and this time, I did alot more research and found out about the nitrogen cycle. I cycled my tank for about a month and finally added my fish about 3 weeks ago. I have (2) 4" ATF and they are doing great so far. Wish me luck!!!