well its not calcium problem because calcium produces red spotted dots when eatting the plant. and most problems happen when ph level is off. that looks like a Mg problem or heat stressed / hot spots.
or your plant needs nutrients. nitrogen can be another key and running that much ph i would try to lower it by .5 for safety
Well, that's completely wrong. You've just been added to the list of poor advice givers that belong asking questions, not answering them.
Did you even bother to look at the pictures. The spotting is clearly dark colored. He's moved past the rust spotting. The leaves are clearly losing their green lushness. There are nutrients required for the verde other than Nitrogen; Magnesium being the most crucial element to the chlorophyll.
The problem is absolutely, 100% related to Calcium. Other deficiencies that could be included are magnesium, nitrogen, and phosphorus. All of this damage could be the result of unbalanced pH levels, or toxic levels of potassium, heat/humidity or just genetics. Spider mites will also cause damage that looks a little similar to what you are seeing, but if you're sure they are clean then I guess this has to be nutrient related.
Dolomite lime will help buffer your pH. Use a good organic nutrient system. Ride it out. They don't look that bad. Get that pH stable at 6.5. Don't do anything drastic. It could be that the needs for Calcium have come and gone, slamming it with Ca+2 now might only lock out Mg+2 and K+1. Take it slow, concentrate on slowing the problem and keeping new growth healthy and happy.
I find my skunk related strains need extra Magnesium in week 3 and they run heavy on calcium until the 1st week of flowering. Maybe this is similar.
