hi i have this hot tub thats just sat here for years and i'd like to make it work again.. i really have no clue about them and was wondering what this part is (the thing sitting on top of the pvc pipe) and why its making this loud and terrible sound when turned on? it seems to be some kind of aerator or something as bubbles start coming out of the jets when it is turned on.. do i need to replace it with some new updated system or just get a new one? thanks

That's an air blower.. and they usually make a loud and terrible sound (they sound like a vacuum cleaner)... however, you may also have bad bearings in it

hmm thank you for the response.. is there any quieter alternative to this or am i just going to have to deal with a loud sound.. never heard one like this before? maybe they're usually place farther away from the spa? thanks