So my boyfriend just gave me a 75 gallon aquarium for Christmas. We have water in it, the filter going, and we put the recommended dosage of Prime in the water. 

I’ve never had a tank bigger than a 20 gallon, and I am wondering if there is anything special that I need to do, or if I need to let the filter run for longer before I put the fish in? 

Also, what kind of fish would be good for it? We already have a baby Eclipse Catfish and a Raphael Catfish that we plan to put in, and I want some clown loaches, but are there any others that are good?