e404ada8_Tank_Aquarium_Water_Parameters__Water_Parameter
[Value] ~400 ppm [Importance] Calcium is another essential element for coral health in a saltwater aquarium. According to the Drs. Foster and Smith chart, natural coral reefs tend to have caclium levels between 380-420 ppm (parts per million). For simplicity sake, I find 400 ppm to be a suitable approximate value [Water Parameter] 
Calcium
A l k a l i n i t y
A m m o n i a
C a l c i u m
N i t r a t e
N i t r i t e
p H
P h o s p h a t e
S a l i n i t y
T e m p e r a t u r e
9 Most Important Reef Tank Aquarium Water Parameters
Water Parameter