Strange color next to inlet

[DevM]

kids moved the water inlet and after a couple of days I noticed this sandy color in the step.

pool store tested the water. No iron or other metals. Any ideas?

pool chemistry seems fine.
ph 7.6
Chlorine about 1ppm
TA 100
CH 363
Indoor
Ozonator
Heater
Water is clear

 

[mknauss]

Welcome to the forum!
Put some vitamin C tablets in a sock, crush them up, and set the sock on the stain. If it disappears, it is iron. If not or it darkens, it could be copper.
I see you posted pool store tests. We do not provide guidance based on them. I assume you have low or no CYA with an indoor pool.
I suggest you read ABC's of Pool Water Chemistry.