Can make a mix of professional substrate like the fluval one, there are other brands of good substrate too, you can mix it with sand, corys like my Fluval only substrate.
The bad thing with using this substrate only is that it's hard to make carpeting plants to root for the firsts days, they unroot easily.
You can use sand only, and put ferts caps deep under sand to make plants root easier. Sand only substrate make it harder for plants to root