I shoot for .05 to .08, but do not see any problems at .1, just means I am ready for a water change or add some gfo. I think you should check your nitrate if your corals are looking hungry? Nitrate I shoot for 5 to 10, but do not worry to much until it hits 25 to 30 range.
When my numbers start to hit the top numbers of the range I shoot for I cut back on fish feeding and adding extra food to the tank for corals And clean my skimmer cup. Within a few days I am back down to bottom numbers of the range I shoot for.
I can tell when my Phosphate is creeping up towards the higher end of my range when my glass gets algae quicker than three days after cleaning as a gauge. I try to test once a week, but I do check my alk every other day.