Orange Blotches On Pebble Sculpture

[guppy2198]

Hi everyone. I have noticed weird orange blotches on my pebble sculpture in my biube. Are these just trapped bits of food that have got mouldy?. I gave it a clean and they came right off. However, some advice would again be much appreciated as I don't want it to harm my fish.
Thanks.

 

[Skins]

Hi everyone. I have noticed weird orange blotches on my pebble sculpture in my biube. Are these just trapped bits of food that have got mouldy?. I gave it a clean and they came right off. However, some advice would again be much appreciated as I don't want it to harm my fish.
Thanks.

Hi Guppy, have the blotches come back after cleaning your pebble sculpture?

Keith.