At 5 micron, it's time to start making shorter wets and being careful of the wetness of the work. Better is to add some dishwashing detergent at this step (12 micron also) to insure a longer wetness of the grit. Sleeks seem to happen when you try to stretch out the wet and the edges tend to dry more than the center and thus the grit/glass clumps and makes a scratch in the glass.
The best thing to do is to grab a magic marker and mark a bunch of the pits you see and see if a short wet will get rid of them. If so, then you are fine. If they stay for a while, you will have to go up another grit size or maybe more and get rid of them.
You WILL always find some deeper pits than the run of the mill and that's because of the basic process that is happening but those pits should be erased with the next wet.