sponge identification

Hey guys! So this tank has been set up for almost a year now and all of the coral is thriving! However for the past month or so these what I assume are sponges have cropped up EVERYWHERE that isn’t exposed to light. Are these indeed some sort of sponge? They aren’t worms or anything as they are...

The ATO in my nano overflowed the tank, and this is why: Can I feed this stuff to my watanabe angel in my 90g by including it in the frozen fish food mix i make with a food processor? If so, do I need to rinse it or clean it somehow before adding it?

Hey guys! I woke up this morning to a white sponge growing under our torch coral and I was wondering if it was harmful and should be removed :)I've attached a photo. Thankyou in advance!

I have noticed a purple sponge-like mass growing at the top of my mixed reef tank. In the last 6 months it seems to have accelerated in size and a second growth has appeared in recent weeks. Should I be concerned that it’s taking nutrients from my corals? If so, what are the best ways to remove...