Hi, Marianne- I think I found a way to add links to photos relatively anonymously. Here's what I was trying to upload the other day.
The larger flecks are windblown grass debris from the yard guy coming earlier that day. See the "cone" of bubbles outlined by the light? Second photo is filtered for blues and I highlighted by drawing on the photo the angle. Those are tiny bubbles that I suspect are CO2. When there's a lot of them, the water looks cloudy.
photos.app.goo.gl
photos.app.goo.gl
I got lucky and noticed last night that the spa still does cloud up with those same teeny bubbles when the heater first runs to bring it up to temp. It clears very quickly. Today the wife was in the spa and I was using the "hose trick" to try to track down this ongoing suction side air leak. Somewhere in my spraying of water the prime in the basket improved and immediately my wife mentioned the water clouded up. I suspect this is because high TA water is getting sucked through the leak and immediately offgassing to try to restore equilibrium. The only thing I can think of when I noticed it last night would be the rapid pressure / temp change of the water spinning through a hot heat exchanger. These are different size bubbles from the normal "air leak" large bubbles and they happen everywhere at once in the water and dissipate quickly.
This is the water before, heater and pump are running, but not yet up to temp. Probably below 90 degree water here. Notice a few very small bubbles made visible by the light.
photos.app.goo.gl
Then as the water increases in temperature, very rapidly, the water gets very cloudy. This was not just bubbles spewing from the returns, it happened all at once. They stick to and grow on swimsuits, hairs, skin, everywhere. When they're knocked loose, more bubbles immediately start forming where the old ones were.
photos.app.goo.gl
photos.app.goo.gl
And then, as the temp continued to climb, the water quickly cleared back out and back to "TFP clear", but there were still bubbles visible in front of the light. Bubbles quit forming on swimsuit and hairs.
photos.app.goo.gl
There's no evidence I had algae growing in my pool when I first came to TFP and started this method, but my water was cloudy. I didn't have to SLAM my pool to clear the water. I never did an OCLT, and I don't recall having had CC above 0.5 (or much change at all ) on any DPD test. As soon as I put the first few gallons of MA in my pool, the water immediately cleared and has only improved as I've continued to lower TA. My conclusion is that the cloudiness was a combination of CO2 and calcium dust from the Cal-Hypo I was using up before switching to liquid.