Northern Light Auto by CrossboneGenetics

For the most part a good week, but some issues popping up in the last few days. At beginning of week all was good, plants showing signs of flower and good color and looking happy. Third day of the week notice that the front right plant (self topper) was looking kinda sad. Next day the back right also looked sad. This was right after watering, so I check PH and it was around 5.6 where i usually keep it 5.8-6.2. So I PH the water, emptied the trays and let them refill with 5.9 PH from the reservoir. Plants looked happier an hour or so later. Checked on them in the morning about 2.5 hours from lights out, and all 4 plants looked droopy. Later when lights came on the two on left (airdomes) were perky but the two on the right while looking better were still sad. Checked again at lights off and all 4 girls are dropping hard. So today (day 7 of week) while I was at work I may have figured out the issue. The base nutrients I've been using are about 3 years old! I get home, dump the trays and reservoir, full clean (again) and refill reservoir with NEW nutrients. I've never seen the floats and trays SO dirty before! Brown sludge on everything, it's like the nutrients weren't properly mixing, probably due to age. Already had a full set of base ready to be used, just forgot about it 🤷‍♀️. So it's about 3 hours after the refill, and all the girls now look better, even front right is almost praying now. As a precaution I also raised the light by 2", bringing the PAR to 580. So now it's wait and see, hoping that they keep looking better and keep on doing their thing. There was quite a growth spurt, especially on the two plants with airdomes. Almost doubled in size this week and they're easily 10" bigger than their sisters who don't have the domes.