I am new to a panted aquarium. I am in the process of setting-up a seahorse tank (erectus) and need to get some macros that have some height. I have seen a couple of sites that advertise "red kelp on rock " (Fosters&Smith & Seawater Express") and "red grape"--what are these? I am worried about using caulerpa due to the sexual/care nneeded for pruning. are these types of caulerpa?