Bought a Hotspring Grandee NXT 6 weeks ago. Everything ok first 6 weeks. This weekend, cleaned filters and added a little water using a new Clean Screen filter. Next morning, water was brown. Chlorine, PH and alk. were all ok. Tried to shock. Didn't help. Water test indicated high metal content, and suggested adding Spa Metal Free. Dealer recommends draining and starting over. I don't understand why this has not been an issue until now. Would the Clean Screen add metals? First time I've used it. I ran water through it for about 30 seconds. Was gray at first, but quickly cleared up. That, and running the spa filters through the dishwasher were the only variables. Any advice?