astroprojector said:Once the FC goes down to below 5 I might shock it again, just to get rid of the algae.
In your original post you said you had an algae spot to the left of the steps. That's the shady area in the photo, correct? It's not unusual to get some minor algae growth in shaded parts, especially when combined with lower circulation there.
Rather than shocking the pool again you could just pay particular attention to that area when you're brushing.