Sad leaves on a previously happy Blue Dream Auto

Flowering is 8-10 weeks for Blue Dream, youre right on schedule. I wouldnt worry about it.

Non ti preoccupare, le foglie più grandi e vecchie sono le prime che vengono usate come riserva di nutrienti , di conseguenza, visto il periodo di crescita in cui ti trovi , la pianta sta semplicemente seguendo il suo decorso di vita! Anche se tu le dai da mangiare lei cercherà lo stesso di fare il suo percorso naturale , praticamente è come se per la pianta ora sta arrivando l'autunno...in autunno le foglie diventano gialle!

I think this is over feeding/ nute burn.. which could be locking out other nutes like calcium which is why you see some calcium deficiency signs, and yellowing leaves as well.. Hard to say.. but if your feeds are above 750 PPM or so that’s pushing it for an auto and likely is the case

I'm not familiar with TPS, it seems to be a liquid based food like AN or GH I don't think its your lights, and pot size is good. I would say they need more food and a small PH adjustment. Maybe a little bit of nitrogen based off of the last 2 photos. The first pic makes it look like it could use a bit of Magnesium or Potassium. CaMg could take care of nitrogen and calcium and magnesium issues. Then the potassium question could be solved with some kelp meal or maybe their bloom?. One thing that sticks out is the PH of water in your current diary is 6.4, if that's the same setup as this, it PH is high for a coir grow with liquid nutrition. normally that's pegged in around 5.5-6.2 Try the above and see if the results happen. Some of the nutrients are mobile in the plant and will improve if they are not late stage deficiencies, others will not and will only affect new growth. Happy Growing!