I am new to the hot tub world but I am mechanically inclined. The hot tub we pruchased has 3 jet nozzles missing. One came out in my hand when I changed the direction of the jet. I had small ball bearings in it but the jets themselves still operate. Can I replace just the nozzle or will I need to replace the entire jet assembly?

Any chance of a picture? How about a brand or model number?

If you know the brand of your spa then getting new jets should be easy.

Most brands use generic suppliers for Jets so for example, many of the Aussie brands are interchangeable.

From experience, most modern jets will pop out if you twist them counter clockwise, until you feel some resistance, then apply some more pressure and it should pop out.

As ROBO100 says, a picture and some dimensions would be a good start for help here...

Good luck!