Does your tub have air control valves? Do the bubbles stop if you close them?
Do you have full pressure out of the jets, or does it feel a little weak?
Here's an interesting wrinkle. Customer service at Dynasty Spas and the Service Tech says :
The pumps have bleeded tubes on them to keep "air lock" from occurring. My tech sent me the following in response to your previous email;
This is not the first time that I have heard customers complain about the tiny air bubbles, but their complaint was the opposite of yours, as they also had a "fizzing" on the top of the water.I went down to the production floor, to the water test department this morning. We ran 5 different spas and all of them cleared of air and was crystal clear within seconds of turning the pumps off. Upon seeing the video the customer has sent, his spa is operating normally as far as we can tell.
The leak that was repaired on the drain is on the suction side. It could have been sucking air into the system causing the fine air bubbles.
Also, high TDS (Total Dissolved Solids) will cause this. As air is injected into the water through the jets, the air temperature is colder than the water, the sudden temperature change when the air mixes with the water, under pressure of the jet, can precipitate dissolved solids and tiny air bubbles appear, once the jets are turned off and water temp warms everything re-dissolves back to clear water.