Hi, I am a new owner of a ten gallon tank. It all started last week when I overheard my sister in law talking about my niece's fish. It is a male betta and she had it in a bowl with very little care. They were talking about throwing it in the pond by their house. I told them that I would take it. The water on the bowl was putrid and I was surprised to see the fish was even alive. Knowing very little about fish I immediately changed the water and cleaned the bowl. Knowing what I do now (which is still very little) I am surprised that the above intervention didn't kill him. Any who I bought him a ten gallon tank let the filter work for a day and put him in there. A few days latter I went to the fish store in my small town to get more fish. The lady who runs the place, a sweet lady who has been in business for years told me that I could add up to 7 more fish with the betta. So I got 1 Bella shark, 2 tiger barbs, 2 clown barbs, a orange fish (she said it was a sempae? Hard to read her writing) and a bottom feeder (she wrote plex). I also used real plants, some ferns and a couple of Anubia. At first my fish were very active but I started noticing them slowing down a bit. I did some research (something I should of done before I bought the rest of the fish) and learned about the importance of cycling. So I have been testing and my levels of nitrite and ammonia were high. I did a 20 percent water change which actuallly killed one of my tigers. I added the water conditioner and kept the water in a bucket in my house for a day before adding it to the tank. My question is how often should I perform water changes? I have heard conflicting reports on on doing it too much and I am kinda gun-shy after the tiger incident. There is just so much information and misinformation out there it is a little overwhelming. Appreciate the help and looking forward to some good advice.