Hey every one i have a 36 gallon reef tank and i have started to see these long stringy thing that looks hard what is it ? Is it go or bad and should it stay in my tank ? And i also have this sponge thing that is white is that bad

My toadstool started getting these spots about 3 days ago thought maybe he was going threw a funk stage but thinking something is defenatly wrong know...What is this ?should i give him a freshwater bath 50/50?or rub him with some luguls solution..HELP..everything else is fine including my new...