Dosing calcium 300ppm to 400ppm one shot.

Why do you think it unlikely? I've tested using two seperate salifert kits and get the same reading over a period of maybe.... three years. I get higher reading in my tank after i dose two part. I have read everywhere that the natural sea water calcium should be higher... but from my experience it's not.

 

same here. Just don't dump it all in at once. I do mine slowly and try to avoid it clouding up. Still all done in an hour or less though.

 

Calcium around reefs have been stable for 1,000s of years and it would take 1000s to millions of years for it to change any measurable amount.

Where precisely are you getting your saltwater? This might easily explain the discrepancy.

 

I wish I lived in Jamaica.....

 

Here.

 

I've dosed magnesium in the drum. Mag WAS 1050 Calc 380. After single dose Mag is now 1500 and Calcium is now 400!!! I did NOT add calcium. is this normal? Alkalinity is stable and PH has remained at 8.2.

 

I spoke to a marine biologist friend that works in the field about calcium and magnesiun levels on the reef. She says that there is noone that she knows that tests for these params on the reef down here. She says I may be able to find answers on corallist . com

 

WOW. nice place to get water change water!!!

BUT, a salinity of 1.030 is too high - especially if it's from the ocean.
I suspect your refractometer isn't calibrated correctly...

Get some 35ppt calibration solution.

 

This is the reason why we told you to get your mag. at the correct level.
Yes its normal.

 

K, will try.