SPL is a term Mark's using to refer to the AG pool pump ratings. I also need to ask him about it.

ONLY use DE to test your filter to make sure it's working: if it blows through the filter, you know your filter needs repairs (maybe, sand).

We need to back up here: it sounds like you may have been asking about your pump / filter combo, because you have an algae problem? If so, spin that off into the Algae section, post your test results, tell us whether you have (or have ordered) a K2006, link back to this thread for equip info . . . and then let us deal with algae THERE, instead of here.