BGA on willow moss

[mecedesfish]

Hi,
My willow moss have some BGA on a small part in my DW. I pull it away and notice that after 4 day it appear again. There are some dark green spot on other plant leaf.

Is this very common with willow moss or therre are something amiss with the water perimeter?

[Plantbrain]

Generally low NO3's, add more KNO3, if this does not work, a 3 day blackout will kill it when added with KNO3 dosing and then KNO3 then after.

Regards,
Tom Barr

www.BarrReport.com