Cyanobacteria , it is more likely that a combination of improper lighting, an abundance of freely available nutrients and a stagnant low-oxygen environment that hasten the bacterial growth. Tanks that exhibit this red slime, or blue-green algae, growth often have good water quality (low ammonia, nitrite and nitrate levels) and are otherwise unremarkable. Instituting a clean-up crew in a marine aquarium can help reduce the slime but only treats the symptom of the problem, not the cause. The Red Scarlet Reef Hermit Crab is the best option for this method. It will readily devour any red slime algae in the tank. Unfortunately, there are no freshwater fish that graze on this “algae” and standard algae control additives fail to alleviate the situation. In a freshwater situation, removing it by hand is possible, but takes a significant amount of time and effort. There is, however, a procedure that can eliminate this particular bacterium from your aquarium, either marine or freshwater, in less than a week. The method for completely removing Cyanobacteria involves a multi faceted approach including limiting or changing out lighting, modifying the tank feeding schedule, physical removal with a gravel cleaner, lowering tank temperature and adding additional aeration to the tank. Although this combination will eliminate the appearance of Cyanobacteria, there will still be minute pockets that survive, they will be so small that they won’t be visible, and you’ll still have to maintain an environment that won’t allow the reappearance of the bloom.
If it's spaghetti worms which I think it is you are probably feeding way to much I have some in my tank they are totally harmless and help clean but you have quite the abundance lol I would cut back your feeding schedule