ok, heres my advice..
1.) throw out all of the filter pads and everything in the filter that is a "consumable". Just get rid of them and buy new ones
2.) manual remove as much of the hair algae as possible, by hand
3.) install new filter media
4.) start water change, and siphon as much "dirt" or
detritus as we call it out of the tank. remove about 2-3 gallons, but no more.
5.) replace removed water with freshly mixed saltwater using
RO/DI or distilled water, not tap water.
this will get you started, but will not "fix" your issue. only time and continued work will do that. in normal tanks i also recommend removing the bio filters (bio balls, ceramic plates/discs etc) they only lead to more
nitrate production
next would be to continue water changes of 1-2 gallons every week (forever)
during this time you should also check your water chemistry and inspect and clean/replace all filters media. failure to clean the media will cause these types of algae issues
and finally for the bristly worms, dont worry about them, as you reduce the excess nutrients in the system there population will be reduced. besides that, they are harmless, they are also some of the best scavengers you can get in your tank..
