I would say that if you think your water is looking less sparkly, trust your eyes. This may just be my experience, but when I recently bought the magnetic stirrer thing, it had my FC at a full ppm less than I was getting when manually swirling on the FC test. I had always run my FC on the high side, and am grateful I had if in fact I thought it was 1 ppm higher than it really was. Couple that with the fairly wide margin of error on the CYA test and I'd say running a little high would cause no harm and potentially ward off problems. Of course, this is just my two cents and you should let the experts (I'm not) weigh in.