Zoa White strings?

[Matt3586]

HI all, fairly new reefer here. Had this Zoa for a little over 5 weeks now and all has been smooth. He's grown without incident until recently. 2 problems. 1, it seems to be impacted by hair algae. I think a peroxide dip might be the best approach. And 2, there's a white stringy substance growing between the polyps as well as a vertical tube. Quasi transparent. This is causing the coral to close up. Any ideas on what this is? Or best approach? Pictures attached. Thanks for the assistance.

 

[RSnodgrass]

Most likely a sponge

 

[G Santana]

Looks like a sponge, the peroxide dip will kill it

 

[RSnodgrass]

Start with peroxide

 

[Matt3586]

Thank you both. I'll proceed with a peroxide dip this evening and do some more research into sponges.