Add more filtration with filter wool if you want clearer water. I run 2 x fluval 405s and 1 x Eheim pro II 2028 on my 4ft tank. Purigen is fantastic, but in a planted tank I don't think it's needed. African and marine tanks do well with it though. When was the last you recharged it, and how old is it if you haven't bought it brand new?
I like the way your crypts have matured.