Update: I observed them for a few more days, and concluded that they are infact alive. I see them floating around in the water and when they land on something they just stay there and start opening up again, exactly like anemones. I did a little bit of research and found Vorticella? They do look similar, but the ones I'm seeing in my tank are always clumped together in a dandelion shape. I'm still considering some type of hydroids or vorticellla, but I'm not really sure yet. I'm not planning on keeping any shrimp here, but I'd still want to get rid of them since they aren't pleasing to look at. The tank is fairly new so I believe that they did multiple from all the organic particles in the water, I recently did a replant too so there's tons of detritus. Thanks for the advice though, I'll be doing more water changes for now. I'm curious if fish like guppies would eat them? maybe raising the tank temp will get rid of them, or maybe just tannins?
Here are some more pictures
