If you are referring to the three or four in the middle that are closed up Thats nothing to worry about I don't think.. maybe they have caught or snagged some food in the water .. Or even it could be a speck of algae if they do not reopen take a Q tip or old soft tooth brush and gently rub them off to clean any algae that may have grown on them.. But I'd give them a few days they looked fine to me.. _________ Some of the world's greatest feats were accomplished by people not smart enough to know they were impossible (Doug Larson) | 
