thanks everyone for your comments. I am happy that the tank is finally looking like it should and corals are showing good growth and color. i'll try to post new coral photos soon.
I have started calk/alk supplementation seriously now that there are numerous acros in the tank. there has been a lot of discussion on some forums on the Balling Method. for those who want to read up there is a lot of info I can point you too, as i've been reading as much as I can. I've found a great deal of the critical info, like how you do it, but still have many questions. I would love to hear of others who are using this method to supplement about their practices and results.
here is the basic recipe. this recipe is a modified balling light (and is very similar to typical 2-part).
jug 1: calcium chloride (recipe 1 1gal kit from bulk reef supply)
fauna marin Strontium Barium Complex
fauna marin Heavy Metal Complex
jug 2: sodium carbonate (recipe 1gal kit from bulk reef supply)
fauna marin Iodine Fluoric Complex
jug 3: Magnesium chloride/magnesium sulfate (again from BRS)
fauna marin ultramin S
dosing is automated by a Litermeter III. i started with 30ml of each Jug added daily. by measuring the cal/alk/mag levels every few days i have adjusted the additions to keep the parameters in range. right now i am adding 70ml of calcium, 40ml of alk and 40 of magnesium. i am still working out the quantity of the magnesium addition, and expect that all the amounts will need to increase as coral growth accelerates.
true balling relies on adding NaCl free salt with the magnesium and the removal of equal part tank water to balance the salinity. for me balling light is easier, and the negatives are countered by weekly water changes. balling light also uses sodium hydrogen carbonate (traditional 2-part recipe 2). the choice of alk additive was for no other reason than its what i had and others have shown it to work fine. although eventually I may go to a true balling and see how it differs.