Rescaping but some rocks are covered in yellow sponges

[Leon821019218]

Good afternoon all I'm going to do a rescape on my tank because I'm not happy with it and I want more open space between the rocks and more open area's on the sand bed. I am putting a plan together but there is something that worries me a bit.. There are a few rocks that are covered in yellow sponges and because some of these rocks will be out of the water for a while, I'm worried about die off which may cause the release of possible toxins in the air or in the tank when I put them back. Is that something to consider or do I worry for no reason?

 

[Dburr1014]

Not all will die.
Not enough to cause any problems.
Post pics when you're done!

 

[Leon821019218]

Ok thank you! I hope I won't forget to make photos, but when I do I'll post them