Hello, Today I bought a new 30 gallon tank off craigslist. While transporting I left about half the water in it. When I finally got it home I filled it, and tested the water. Here are my levels, Ammonia between 0 and .25, nitrite .25, and nitrate around 40. I know that having any ammonia and nitrite is bad, along with my high nitrate. How should I fix this problem? There are 3 Cichlids in it, I think two are Jack Dempseys, not sure what the other one is, will post pics soon. Any advice on what to do with water parameters?