Could these possibly be algae? My numbers are:
FC has never fallen below 3. These specks are confined to one corner of the pool. They are black or a very dark brown and very difficult to pick off with a fingernail. They do not feel the least bit slimy at all. Could it be algae? I cannot guard my pool any closer than what I have been. How could algae have possibly formed, if it is indeed algae.
Edit to add: Cannot be brushed off with the bristles on a Catfish pool vac.