Sponge of some sort?

[i cant think]

I’m really sorry about the blue photo however, I saw this in my tank a few days ago and thought it was a sponge, I’ve been getting very anxious recently and thought to get a proper ID of it and the species, it looks bright yellow and is relatively slimey if I remember correctly.

 

[Arthacker87]

Seems like it. They grow in lower flow areas

 

[i cant think]

Seems like it. They grow in lower flow areas

That’s certainly a low flow area, the current is just above it and bounces back calmly on the glass

 

[shakacuz]

check your RO/freshwater with a TDS meter to see how much silicate you have in the water. sponges feed off silicate.