Sorry about your difficulty. It sounds like you have high mineral concentration, perhaps copper, which turns green when oxidized. This could be introduced by your municipal water or if you aren't using USP grade epsom salt, it could be contaminated.

You can purchase a simple filter when filling up your pod.

http://www.amazon.com/Garden-Hose-Filter-Chloramines-Pesticides/dp/B007I6MN72

Be sure, when you are filling that you do not run your water heater less than 1/4 full. Sediments rest at the bottom of water heaters and when they get to low, the water agitates and stirs up the minerals.

To fix the problem, keep oxidizing. I am assuming you are using non-chlorine shock... keep using that and keep it at 200ppm. Run your filters as much as you can and twice a week add a clarifier to clump the dissolved particles. Clean the filter element regulartly through this process and it should come back to normal within a week.