alk,ca and mg

[reefnut]

ive had my tanks running for just over a year now.at first i would just test for am,nitrate,nitrite and ph.after i had solved most of my problems with those i added a few softies and began testing alk and ca.my ca stays around440-480 and my alk is around 9.,5 dkh.i have always had problems with my anthelia and xenia,they seemed not to grow and they would be curled half the time i looked at them.my next test kit will be mg and i have a few questions.first i would like to know if anyone can give me a link to a table showing how alk,ca and mg relate to each other and what there ideal levels are.and if my levels are low how can i add more mg without affecting my alk or ca which are both a levels im happy with?thank you