Aquapure 1400 maintainence

I am using an Aquapure 1400 system in my 12,000 gallon plaster pool.
I seem to have a significant amount of build-up, (calcium??) in the salt cell.
A pool service guy reccomended that I soak the cell in a bucket for water/acid mixture to clean it.

Is this the reccomended method to keep the cell working well?
How much acid should I be using in the soaking solution?
How long should I soak it, and how often is reccomended?

Thanks in advance for your help
Mike

Google is your friend. Try searching for "Aquapure owners manual" and you'll see several links, right at the top, of PDFs of the Aquapure 700/1400 owners manual. In there, you'll get all the info you need. ;-)