I am getting ready to SLAM my pool but I need to know if I just have regular algae or if I have mustard algae.
I am pretty sure I have some black algae next to the skimmer.
I have some persistent light brown/light yellow stains on the stairs and near the drain. They are not pollen as they do not come up when I brush or vacuum. However, they are pretty subtle.
Here is my current pool chemistry:
Free Chlorine 6.5
Combined Chlorine 0
Calcium Hardness 325
Total Alkalinity 100
Pictures are attached.