First of all, hello all. I have just set up a new 15g with a whisper 20 and small gravel substrate. I added two Harlequin's on Wednesday afternoon and a Julli Cory Cat. Temp is at about 74 with a PH of 7.6, Ammonia of .5ppm and nitrite at 0ppm. I wanted to add more fish, possibly another Harlequin and another cory, but I wanted to make sure I could do this without putting my other fish in danger. Is it too early to add these fish, or can I go ahead? Thanks for any help