We are new to this hobby and are absolutely fascinated. We have a 55gal tank, Fluvol 205 canister filter, cyclone hob protein skimmer, 1250 powerhead, T5 high output fluorescent lights (2@ 12000 spectrum, 2@ actnic). 17lbs live rock, 15lb base rock, 1"sand. Our sealife: Occellaris clownfish Yellow eyed Tang Yellow Tang Melanarus Wrasse Red Fromia Starfish Coral Banded Shrimp Anemone (i think it is a long tentacle but unsure) and a handful of turbo snails, an olive snail, and hermit crabs Red & Blue mushroom corals Leather coral (came on a live rock) Radioactive Dragon Eye Zoanthid We are constantly having to add calcium supp to keep it above 380mg/l. that doesn't seem normal. any tips on how to keep calcium levels up so we can support more corals? Any other softies that would be good for a newbie to try? I'd love to get a sand sifting goby but I have heard they wreck the rockscape. thoughts? Any suggestions on which fish would be compatible in our tank? I don't want to overcrowd the tank, so how many fish is acceptable to have?