calcium at 345 ppm

[reefnut]

well ive been using kents liquid reactor to try to get my calcium up around 440 but it just wont work.ive been following the directions on the bottle that say to add 5ml a day until you reach your target.According to the bottle one ml per gallon will add about 33 ppm of calcium.over the last week ive added the equivalent to 2 ml per gallon and no increase at all in calcium.but there is a thin white film now covering all my rock and sand.is this suppose to dissolve over the next few weeks and then my calcium will rise.

33 gal
60 watts t5 +55 watts pc
20 lbs lr
20 pounds crushed coral
3 cleaner shrimps
one green clown goby
one firefish
about 3 snail + 3 hermits
lees air driven skimmer
about 150 gallons flow
some macro

any ideas why my calcium wont rise.my alk is around 11.2 dkh and my ph is at 8.2.Amonia,nitrite and nitrate are almost undetectable.and my sg is sitting at .024.

Thanks in advance for any help.