It will be cloudy until it stops making CO2... It wont stop making CO2 until fermentation is finished (and then you have to get residual CO2 after that)... So dont expect it to clear, while still fermenting... If it starts clearing, then the wine stalled and actions need to be taken to get it going again.. So it not clearing = good signs.
66 degrees is on the cool side, not a bad thing - its just lengthening your fermentation, but that will also help to retain more aromatics and delicate flavors that high temp fermentations "blow out" (literally, with CO2) or transform into cooked-sort of flavors..
Edit: Err.. Said 66 at the top of your post - the ambient temp downstairs - but the radar gun reads 75.. Did you hug it on the way upstairs?
4.0 pH is kind of high.. 7.0 is neutral, and most wines are in the 3.2 - 3.4 range.. Some, like this batch get as high as 4.0 and others come in at 2.8-2.9... But 3.2 - 3.4 is the sweet spot. I dont know if I would correct it mid-ferment, but maybe.. I'd let others weigh in on that and take the concensus then weigh it against your gut feeling... If you do add acid, add half of what you think you need, remeasure and add more - you DONT want to overshoot it, that much I promise you..
The "slime" that rose and sank, had CO2 attached to it, and when you disturbed it, it dislodged enough that that CO2 could carry the mass to the top - then when the gas dissipated, gravity said "Get over here!" something akin to Scorpion from Mortal Kombat
(bahahahaha, I just made a Mortal Kombat reference on a wine forum - shows what generation this guy is)
Sounds like it doing what its supposed to be doing
