I have three feater dusters in my 75g tank. They popped their tops quite some time ago. I was wondering how long does it take for them to get back to full size. They seem to be doing well and i usuall feed them everyother day. But it seems that they are not growing very fast.

If they just through their crowns than it will take a couple weeks or longer. I had a Feather Duster throw its crown and it took about two weeks to grow a new one. Just keep your parameters in check and they should grow back.