Thanks for the suggestions! I dosed some excel this morning, I'll continue to dose every day for a while and see if that helps. I'll also try upping or more frequently dosing flourish comprehensive.
I've tried peroxide as well, algae turns red and dies but always seems to come back.
I definitely don't seem to have issues with the Parva growing though, I started with 1 small pot about 6 months ago and now have about half the tank full of it... I just wish it would be nice and green!