HotTubbin

My husband and I got our hot tub about 3 months ago, so we are still working on figuring out everything. Recently, we have started to have a slight green tint to our water, and sometimes there is a not nice odor. The water is not cloudy--we can still see the bubble design on the bottom of the tub. Also, when we tested our water yesterday, the CYA level was as high as our testing strip would go. We found this very surprising because that has been at the "perfect" level previously. Does anyone have any idea what might be going on? What can we do to fix these problems? Thank you!!