About 1 inch of fish per 3 gallons. Your tank is 60 gallons, so about 20 inches of fish (fully grown). This isn't an exact metric but a very loose guideline. Before getting a fish make sure to check the tank size requirement and care level of the fish.When it comes time for fish which wont be for a bit how many will i be able to have in there considering id like a decent aqua scape