Algae or Decoration peeling?

[SeaHorseQueen]

Hi, I’ve been watching this for a while and this has developed for at least a week. Is this algae developed on the fake rubber or is this a decoration that is peeling? Pictured with my dwarf blue legged hermit crab that happened to be there. Is it a bad algae if so or does it need treatment? It’s the only area in tank like this. The rocks shifted colors to what is pictured. I just want to make sure it’s safe and not going to affect my tank. This is my display tank. I feed just enough that the fish and inverts keep it clean. I’ve had light brown algae before but usually on the sand only during ugly stages in last tank but didn’t put anything fake in there until now.

 

[Jekyl]

Are you sure that the decoration is meant for saltwater? Looks like diatoms but can't be sure.

 

[SeaHorseQueen]

Are you sure that the decoration is meant for saltwater? Looks like diatoms but can't be sure.

Yes, I checked it. It’s been in there since May. It only started doing this. I can’t tell if it’s what you said or peeling?

 

[ABQ_CHRIS]

Looks like algae to me. I would remove it and rinse in RODI or saltwater if you would like to keep it in there.

 

[SeaHorseQueen]

Looks like algae to me. I would remove it and rinse in RODI or saltwater if you would like to keep it in there.

Do you know what kind it is out of curiosity?