RKIN Zip Countertop Water Filter Replacement Filters Bundle by puricom

I have the red constant light, how do I know if I need this filter or the third stage filter?

I bought the black zip model in 2016. i thought i needed to replace 1 filter after 6 months, and 1 every year. which filters do i need to buy??

Is the second stage carbon block (as shown in the description of the initial set of filter for the product), or Granulated carbon (as shown here)!

Orange/ yellow light after replacing the filters? What could be the reason and how to make the system functional again? Resetting is not working.