Ferts?

Whilst at walmart to get ferts for my planted tank, I was told to use reegular fertalizer. Like i would for a yard. Well, they didn't have any for a fish tank and I didn't want to test his theory, so I came home empty handed. But now I wanted to know... Was he right? When he told me this, he poimted towards the Miracle Grow section. just curious, don't want to give the plant miracle anything if it does no miracles for the fish.