Hi Jack. Thank you for your message. When a starter pack is bought together with other macroalgae we will always try to add other macroalgae species for you and we normally pack them as they come. When you buy two packs it might be that you get some similar algae species. I would recommend adding macroalgae when the tank is established and you have the fishes already in for a while. As with them your tank normally will have enough nitrate and phosphate the macroalgae will need to grow. The other nutrients macroalgae will need to grow you normally will have enough when you do normal water changes. In other words no need for any fertilizer :) Just in a macroalgae only tank, or where nitrate is below 2ppm / or phosphate below 0.02 it will beneficial to use a fertilizer or a special supplement to replace the used nutrients.