mustard algae?

[302harrison]

I noticed something orangey-brown on the walls of the pool and on the seat carved into the deep end. (just on a small section of the wall near the seat and on the seat) It was barely noticeable, but when I brushed it it went away. Is this mustard algae? If I do a chlorine loss test tonight and it checks out and the orangey stuff doesn't return, am I okay? Or should I go ahead and shock the pool now just in case? Thanks!

FC 7
Ph 7.8
TA 60
CYA 50
CH 240

 

[PoolStored]

Do the OCLT. SLAM if you fail.
Brushing should be a regular part of pool maintenance. There may be areas that have low flow, brushing moves water and breaks the biofilm on any algae that may form in low flow areas exposing it to sanitizing water.

 

[302harrison]

Okay. Thanks!

 

[JamesW]

Maybe iron.

Pictures?