coralline is great for tank and its a sign of a healthy tank.....it battles all other algae's.....i know that sometimes it can look ugly but personally as long as it's not on my side or front glass, I like the way it looks on the back glass.
as for how to get rid of it....are you sure you are scraping it ALL off the glass....because for it come back in one day is pretty impressive? other than scraping though...lower calcium would help but like mentioned...your corals wont lke it.
i am scraping ALL of it, my dad is even starting to scream at me everyday to clean out my tank even thought i clean it every 2 days i am getting tired.
if you add more corals they will take up most of the calcium and alk and it should drop...i dont believe your calcium is that high though ........i dose my lfe away and cant keep it that high ...is your tank special or something .....buy a mag float 15 bucks .and buy a scrapewr for 10 bucks just make sure you take the scraper out of the water every time you use it
any links on where to get those vic, petco sells them for 50 bucks.
i am planning on getting more corals, mainly zoas. i have to arange a time with skirz to pick up some fire and ice zoas that he is offering at such a low price to me.
coraline is a "low light" organism. When you increase your light intensity(not sure of your system), the coralline will grow in the "shadows" of your tank.