Calcium been running consistent at 500

[siggy]

I recently jumped back into salt again and setup a 40 all in one with 40 lbs live rock and live sand
using reef crystals i consistently had 500 ppm calcium, well the 40 was not big enough so i jumped again and landed on a 75 gallon, this one has a puka shell base, same readings , changed salts a month
later and still the same readings using api then red sea still the same, could it be the live rock 10 lbs branch staghorn skeletons , 25 lb shelf plate solid skeleton and 30 lbs fuji.
i'm using ro-di and weekly 10 gallon changes. my goal is to host acro's successfully.
I have been getting mixed responses that these parameters are great for sps but others are saying that 500 ppm is a little too high and cause for concern.

alk 9.5
phos .5
no additives

 

[Cory]

Its hard to say why but it could be a test kit error. Or are you doing water changes? Whats the calcium in fresh water change water?

 

[lilchris_357]

If you are running ultra low nutrient system (nitrate and phosphate undectecable) you should maintain Ca at NSW levels (420-450), same goes for your alkalinity (7-7.5 dkh). Do you have any corals in your tank?

 

[siggy]

Lots of corals and fish 1 or 2 cube a day photo plankton 1 a week and roids 1 a week for a few corals,large bag of carbon bag gfo and bag phosgard in sump,

 

[Randy Holmes-Farley Verified Community Expert]

If accurate, 500 ppm calcium is fine. There is no evidence of any harm at all.