I am a new reefer and have a 30 gal.with 40 lbs live rock,bak pak skimmer,17000k white and 420/460nm actinic lighting and eheim2222 cannister filter.I am keeping 1 maroon clown,1small yellow yang and 1 small royal gramma. 6 hermits,4 snails,1 fire shrimp,1 cleaner shrimp,and 3 peppermint shrimp,1 green open brain,1yellow polyps about 2 in. 1 green star polyps 4in. 1frag of pulsing xenia, 1 frogspawn.and a small orange sea mat. My water parameters are SG 1.020,ammo 0,kh 240,temp 77,PH 8.4 about,calcium 300,nitrite 0,nitrate 20ppm. I also have 1 buuble tip anemone who is hosting clown. What do you think? how do you get single digit kh readings? Everyone appears healthy I am concerned about low calcium.