Maybe I DO need to add strontium

[sen5241b]

"Oceanic Sea Salt has abnormally high levels of Aluminum, Manganese, Nickel and Zinc. It also has a Strontium deficiency, but is otherwise similar to the other salts. Some type of metal contamination seems a possibility."

http://www.advancedaquarist.com/2005/12/aafeature1

 

[ccCapt]

Salifert makes a Sr test kit. Get 1 and test your levels.
Don't dose anything you don't test for.