windwagen

I wanted to revive this old thread in case someone is still looking for a solution. I recently started having this problem. I replaced the water and it was fine, but a few months later, it started happening again and came here for advice. I wasn't as scientific with my water chemistry, but after reading this thread I checked the water with a strip and put a chlorine puck in the spa. Next morning, the water was green. I checked with a strip again and the PH was too low... I decided to dump in some PH up and the water changed colour right before my eyes! The green cleared up and .... no more coughing! Another strip test and the free chlorine is a bit high. Normally, I use Bromine tablets in a dispenser. I guess I should throw in a puck once in a while too... Hope this helps - and a great big thanks to the previous posters for your infomation!