I would only worry about PE if it is not "normal" for your tank. A really hairy Millepora, for example, that suddenly has no PE... this should be paid attention to. On the converse, a coral with next to no normal PE also has a bunch all of a sudden, then I would get to testing some water since it could not being having a hard time respiring... like too much ammonia or nitrite all of a sudden.
That what i have.. i mean i have millie fuzzy ones, jedi mindtrick monti etc.... when it touch my water after 24 hours during light it wont have any pe. I frag one red planet and sold it to my lfs. Next thing u know pe is crazy....