I have similar issues, on a outdoor blueberry ( one branch pollenated 3-4 weeks into flower ). The buds are size of beer bottles (thats why i want to keep gene ) Should I flower branch full 8 weeks ? thanks in advance.
I had 4 plants under 600, next grow I had 8 plants under same. yeild was exactly same (fluffy buds) . I then switched to 1000 watts , tight buds ,more weight, but had to upgrade ventilation.
With high temps & lack of rain, my well water went up ph 8.2 . I bring it down 6.2, but I did not realize at first & had some lock out (had to flush some plants)
I used stuff called Doktor Doom (from hydro shop, but saw same stuff at hardware store) it worked great for me after 2 applications (about 2 weeks) I haven seen a little bastard since, good luck