Watch where you have that GSP. Its like kuzu of the sea. If left alone it will spread to all the rocks. That is fine if you like that look. Most put on a rock in sand bed to get it from covering other rocks. Once it gets on rocks its very difficult to remove without removing rock.
will it hurt the rocks or mess up anything if gets on them? Also, is it okay to have the GSPs in low direct current? or should they be out of the current?