Hi, I have a vita spa with single filter cartridge, it has two filter return jets about 8 inches apart from each other on the lower part of the shell, I noticed that one return is much more powerful than the other and has air mixed in while the other is much weaker with no air bubbles coming from it. Is this a problem or normal?? Thanks for all help.

It doesn't sound normal, check the nozzle in the jet that is not working, that is what mixes the air and water, it might be clogged.