Sponge.

[mansiz]

My purple sponge have some peeling, why did this happens? Is it because it was contacted to air? But I did try my best to reduce the time it contacted to air to a minimum when I transfer it from the bag to the tank. And do they need light?

[reefrunner69]

More than likely it is due to the air contact. When transfering a sponge, you should put the bag in the tank under the water, remove the sponge from the bag and then pull the bag out.

Yes some need light, some don't depends on the sponge, if you purchased it, more than likely it needs light.

[Biggen]

I believe sponges (not sure on all of them) need a fair amount of silicate in the water to do well. May want to do some research on this...

[SquishyFish]

They also need high flow and low light.