White things are floating around in my tank

[Sheltie]

I just did a 25% water change as usual, but this time when I put the light back on.. Theres white feathery looking thinga floating around. Some are as big as this -> . And some are as long as two inches, others are no wider than a dime. The sizes vary. I picked out some of the bigger ones with a net. This tank has been set up for a few months now.
What could it be? I have yet to check my water parameters, but when I do, Ill put them here.

 

[Rivercats]

You really need to post a picture but the only thing that comes to mind are hydras but they are usually attached to something. Do they look like these pic's?

pictures of freshwater hydras - Google Search

 

[Sheltie]

Im not sure how to post picture from my phone otherwise I would.
But no, they dont look like that. They kins of looked like they had a centerpoint and little feathery things came off that cEnterpiece. Whatever they were either settled or got sucked up the fiter.