Coarse sand definitely helps but it hold quite a bit of water as well. It is good to add to topsoil on in-ground outdoor grows. If no perlite, then vermiculite or a hydroton type inert media. Hope that helps and happy growing!!!
Hi mate, the purpose of adding perlite or vermiculite is to air-ate the soil. Allowing water to drain quickly and sustain moisture and oxygen in the substrate. Adding sand may make the soil less able to drain and maintain field capacity. More likely to keep water where you don't want it. I hope this helps, good luck and happy growing