unknown small blue, spiky, sponge- or macro-algae-looking things all over tank

[stokedmuffin]

While I was cleaning my filter socks today, I noticed there were hundreds of small blue, spiky, sponge- or macro-algae-looking things inside them. After checking the main display, I realized they are everywhere kind of sprinkled all over the tank. Can anyone tell me what these are?

 

[KrisReef]

Dictyota friabilis​

 

[Dread Pirate Dave]

Dictyota friabilis​

Good call! Maybe a mix with Humifusa too?

https://www.google.com/search?q=Dictyota+humifusa

 

[stokedmuffin]

its does look like that im wonder wear it came from tank has been running for over a year . only thing added in the last 6 months was from my main tank . with no signs of anything . three days ago there was no sign of this at all also i'm a little curio's why there are hundred of little pieces all over the tank

 

[KrisReef]

its does look like that im wonder wear it came from tank has been running for over a year . only thing added in the last 6 months was from my main tank . with no signs of anything . three days ago there was no sign of this at all also i'm a little curio's why there are hundred of little pieces all over the tank

Aquatic weeds seem to have seasonal episodes, often with sudden appearance “from out of nowhere.”

Your post suggested that this is what you are looking at?

I have seen weeds sprouting from rock that was “dead” (wet, but no plants) in a tank for a year or two. Same thing happened yearly, until it eventually it didn’t?