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). \n17lbs live rock, 15lb base rock, 1"sand.\nOur sealife:\nOccellaris clownfish\nYellow eyed Tang\nYellow Tang\nMelanarus Wrasse\nRed Fromia Starfish\nCoral Banded Shrimp\nAnemone (i think it is a long tentacle but unsure)\nand a handful of turbo snails, an olive snail, and hermit crabs\nRed & Blue mushroom corals\nLeather coral (came on a live rock)\nRadioactive Dragon Eye Zoanthid \n\nWe 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? \nAny other softies that would be good for a newbie to try?\nI'd love to get a sand sifting goby but I have heard they wreck the rockscape. thoughts? \nAny suggestions on which fish would be compatible in our tank? \nI don't want to overcrowd the tank, so how many fish is acceptable to have?