Orange spots on previously live rock.

[NoohBee07]

Hello everyone,

can anybody tell me what this is? This was a previously live rock and I have noticed these bright orange spots appeared on it. I am pretty new to saltwater and theres so much more for me to learn. thank you!



THANKS FOR VIEWING!

Another question is, i am setting up a hospital tank. there seem to be an ammonia reading of .25 on it. Whats the best solution for this? water change? and if so, do i need to redose the Cupramine? or those Ammonia fizz tabs are safe to use in Hospital tank? And on my reef tank? whats the best fix for a .25 Ammonia reading?

is RODI a must or RO would be good enough for water?

Thank You!!

-Sia