Air bubbles from spa jets

[cybertoad]

I have a quick question that maybe someone can answer. We have a new pool and recently I noticed that the spa jets have air bubbles coming out of them in spa mode or in spillway mode (without the blower turned on.) Our system has a blower with an above ground Hartford loop with a check valve. When the spa or spillway mode is turned off after running, I'm noticing a "bloop bloop bloop" from one of the jets that goes on for about 15-20 seconds accompanied by bubbles, as if water is draining down or air is migrating upward. I don't recall noticing this until today. Does this sound like normal operation or something to be concerned with? Thanks

 

[mas985]

If water is flowing through the venturi jets, they may pull in air even if the blower is off. They are designed to do this. In fact, spas such as mine do not require a blower at all in order to get a decent amount of bubbles. Spas that require blowers are usually designed poorly such that a blower is required to clear the air lines. But given you have a Hartford loop, you may not need the blower at all which to me is a good thing (i.e. less noise and lower power bills).

 

[cybertoad]

We can pretty much get by just fine using only the pump at 3000 rpm. Only if we want the jets to be super powerful do we need the blower. It's nice with it off because you can still hold conversations with others in the spa. The Jandy unit they installed is actually remarkably quiet. Our pipe run is about 60 feet which is probably why they felt they needed a blower setup. Really enjoying the spa but probably won't enjoy next month's gas and electric bills!

 

[mas985]

Given air is far less dense than water (784x), adding more air reduces the mass and thus the momentum of the water/air mixture. So technically, the average force of the stream with additional air is reduced. However, the air does break up the water stream to make it make it feel more massaging/pulsating (i.e. larger change in momentum) which is usually desirable. Too much air and this effect is reduced and you get just a lot of bubbles.