old IO precip. anything to worry about?

[easternreefer]

Hey all. I am getting ready to get my 90g wet. I had a half of a bag of IO that is 3+ years old. It was kept sealed and away from moisture. I mixed it up yesterday afternoon and there is still solids in the bottom of the container. What might this be? anything to be worried about?

 

[Randy Holmes-Farley Verified Community Expert]

It is likely to be calcium carbonate. If the alk and calcium in the water are OK then the mix is good to go. :)

 

[easternreefer]

that is good to hear.. thank you.. I assumed that it was that but.. just needed to make sure.