yellow fuzziness

[greatwit]

Definetly looks like sponge. Harmless, good filter feeder if it lives.

[GaryP]

I got a piece of LR a few weeks ago and just noticed that there is something yellowish the looks like a squished cottonball growing on the back of one of my LR pieces that I did not see before.

Welcome to MAAST. My guess best is that it may be a tunicate or a sponge.

[reeferRob]

Right now the plan is to establish the tank for a while...going to wait for at least 3 months before adding any fish then maybe a mandarin after about 9 months to a year

ok at the risk of sounding odd...
when you mention having macro in the refugium...what are you refering to?

Macro=macroalgae (Good) , ppl use it in their sumps to control microalgae (NO GOOD), and something to cultivate pods and such, some fish will also eat certain Macros, I had a nice little clump growing on a LR and bought a sailfin Tang and it was gone within an hour of putting him in my tank LOL