Lime Stains on white plaster - used Stainfree, need advice

[BB_Sacramento]

I have lime stains on my 13-year-old inground pool with white plaster. I followed the directions for using Stainfree and after 24 hours the stains were much lighter but not "gone". For about 12 hours after pouring the granules into the pool I didn't touch it. Then the pump/vacuum ran for a few hours and I brushed the sides/bottom of the pool last night which was 24 hours after using the Stainfree. Today the pump is running again. My question is, when should I clean the filters? And how long does the Stainfree continue to lighten stains? (Does it only work for 24 hours or ?) If my stains are not completely gone I will be satisfied with how they look now but I'd like to get the most out of my efforts so I don't want to prematurely clean the filters or do something wrong now. Advice?? Also I added 2 ounces of algaecide this morning, although it has no algae yet. Should i also start adding some chlorine too now? or wait? Thanks in advance.