Brown stains?

[cmoore806]

I have a 10 gallon quarantine setup. On day 10 of 30 day copper power treatment (prophylactic). My copper is between 2-2.25 as is my plan. I have noticed this rust color deposit on the PVC and mesh bag of sea hem matrix and on the glass bottom. I know I’ve seen it incidentally on pictures on reef2reef. Any ideas what it’s from or what’s causing it??

fish are healthy appearing and temp salinity and pH are stable. Ammonia is 0.

 

[F i s h y]

Others may chime in but some sort of algal growth maybe? I'm not sure. Typically would show most obviously on a white surface to begin with.

 

[moz71]

Basic algae or even diatoms. Nothing to worry about. Always happens.

 

[cmoore806]

doesn't look like algae, it looks like rust spots

 

[akaemu]

Did you wipe?

 

[cmoore806]

Did you wipe?

I can't remember if it was front to back or back to front, but yes I'm fairly certain I wiped.