We have a Coast spa-2 years old, was winterized and sat for 1 year during remodeing. Flushed it out, filled it about 5 weks ago and have been trying to get the water chemisty correct since then. We are using Nature 2 and non chlorine shock with dichlor once a week. The water is very cloudy and yesterday when I switched out the filters the one that had been in the tub was covered with clear slime. We cleaned it, ran the tub open for a couple hours, ran extra cycles with not much improvement. Now the dealer says we may have "water mold"? Has anybody ever heard of this? He said to put 2 oz. of dichlor in now and again in a couple hours-may need to repeat for a few days. Would I be better off to just drain & refill the spa? Thanks for any help you can give us> Valerie

Water mold is caused by a microorganism that has, unfortunately, become resistant to the biguanide. In order to treat the problem, I suggest that you drain the spa and refill with fresh water. Add some quick-dissolving chlorine or non-chlorine shock and make sure that at least a 1-3 PPM level of Free Chlorine persists overnight. Add more shock, as necessary. This will destroy the water mold on the surfaces and in the lines. Resuming maintenance on biguanide will require that you once again, drain the spa, refill and start from scratch or add sufficient chlorine neutralizer to drop the chlorine level to zero. Once a biguanide-resistant microorganism has developed there is no guarantee that it will not return, even after successful treatment. For this reason, I suggest that an alternative sanitizer be considered: chlorine, bromine, ozone, ultraviolet, mineral purifiers, ionization or a combination.

How do biguanides relate to the original question?......... that's 1-1/2 years old.

watermold can be more prevelant in a biguidine water. It is mainly killed with a strong oxidizer like dichlor - but only about triple the amount ever 2-3 days (along with testing) till it is gone, keep an eye on the pH so it doesnt get too high