pallan which red sea salt do you use? the regular or the reef pro mix? the reef pro mix is supposed to have a lot of calcium in it. i use the regular stuff now and my calc would normally be low.
purple up is not an additive to grow purple coraline algae. it contains no biological contents. it is really a calcium additive, with a few other trace elements such as iodine for inverts. in that respect the product works very well in raising calcium levels. if your calcium is maintained high enough, then the coralline algae that will be most prominent are the purple strains, as opposed to the red and green. so it really just promotes the growth of it, by making the conditions more suitable.