I was getting a lot of foam in the spa when adding air to the jets,
the local pool supply store where I get the water tested just kept telling me that it is caused by excessive organic matter in the water but couldn't give me a real solution so, asking doctor google I came across this product. It works great, I paid attention to other customers reviews and experiences and got the job done.
I kept scrubbing the green water line as the water level dropped, and rinsed it a couple of times with fresh water at the end, just to make sure.
Now I have very clean water and no foam whatsoever.