I've had a persistent, unpleasant odor in our spa water for about 9 months. Somehow it sticks around even after I change the water. Lately I have to change the water at least every 2 months and sometimes as frequently as every month. When I change the water, I drain and fill and run it for an hour and then drain and fill again. I scrub down the shell and cover with a bleach and water solution and soak or change the filter. The odor is sort of sweetish and musty. I can start smelling it within a week of changing the water and it increases with time. I'm a Baqua Spa user (everything else seems to give me a rash) and everything seems balanced OK. Is it possible that something (mold/mildew) is growing in the air or blower tubes that hook into the jets or the blower? if yes, how can these best be cleaned. Any other ideas or suggestions? I've used Baqua Spa for years before this and never had this odor problem before. Thanks for the help.

Does your spa have an air blower on it?

Yes, it has a blower that sucks air from beneath the cabinet and creates bubbles that come up from the seat bottoms. On my spa it's called turbo air, and it has three speeds. It also has valves on the top of the sides of the spa. When the valves are opened air is introduced into the jets. Could either of these be harboring mold or mildew?

Yes absolutely.

You need to cycle that control valve to be sure that the air injectors are getting the blower air, (not the jets), as if this is not done on a regular basis, then your entire air injector system will turn into a septic tank.

If your controller is not digital/automatic and cycles on and off the blower periodically, then you really need to do this at least twice a week (more the better) for about 15-30 seconds to flush out the bad stuff and let some of the normally sanitized water back in.

Pageup - Thanks for the reply. My system is digital and cycles twice a day. Could it still be something to do with the air injector system? Do those lines need to be cleaned out? If yes, how would I go about cleaning them out?

Lest I get blasted on my own forum for my chemistry advice....

With a freshly filled tub, I'd shock the heck out of it (double dose chlorine shock, and nothing else) and let it run for a day (on a low temp setting - like cold ok?), drain, refill... and go from there.

Pageup - Thanks, I'll give it a try over the weekend and let you know how it goes. It may be a few days before I can tell if it's working.

When you say you cleaned the cover, did you actualy clean the inside , or just wipe down the outside?

Dr Spa - I usually just wipe it down with a strong bleach and water solution on the underside of the cover. Do you think I need to take the foam inserts out and clean the whole thing inside and out? It's a pretty good quality cover which I purchased in June of '03.

Pageup - Can I use dichlor for the shock? It's a 350 gallon spa, how much should I use?

Mildew inside the cover, regardless of the quality, is not unheard of.