Personally if your destined to get coraline you will get it, with proper calcium and alk and ph levels. No need to add anything. I have goten coraline to start growing in a one month old tank by keeping cal and alk levels at or above the max levels during initial cycling, and its doing great as far as growth......probably too good. At the most I would use B-ionic 2 part doseing supplements, and nothing more. Keep sg 1.023 t0 1.025 and a ph of 8.3 or more and it will still grow when its ready.