Amnesia Haze-ILGM-Photoperiod-RDWC

OBJECTIVE -Plant A moved to separate 5 gallon bucket today due to size; she is now 29 inches (this is temporary) under a 600W HPS bulb at 50% power with an air stone providing oxygen . Plant is supported in clay pebbles. -1 more seedling added to the setup -pH maintained between 5.5-6.2 with adjustments made every 24 hours (goal 5.8), although pH measurements may be inaccurate due to meter malfunctioning -159 PPM in aeroponic setup; 200 in bucket -Exchanged aeroponic water bath again today (will continue to do this weekly - used 2 gallons) and continued using the ratio of 2/1/0.5 of FloraDuo A/FloraDuo B/Calimagic + 2 mL Hydroguard (beneficial bacteria solution) per gallon of water -continued air circulation and 24 hour light exposure SUBJECTIVE -pH meter began malfunctioning two days ago - when placed in solution, the reading decreases over a period of ~20 seconds (did not used to take this long to read, & beginning measurement is nowhere near end measurement - so true measurement is unknown). The meter is getting progressively further and further from the actual pH of a control solution. Waiting for new meter to arrive in the mail. -The slower growing plants have grown slightly, but are not experiencing growth anywhere near that of the larger plants - result is all plants are at very different stages of growth. Largest plants (A&B) look relatively healthy. -Older leaves have continued to develop spots, but this seems to be slowing down except for plant C - all the leaves from the first node have turned crispy and disintegrated, and browning is much more progressive on newer leaves than on the other plants. Still unknown exactly why this is occurring. CONVERSATION -Not knowing the actual pH is frustrating, especially in light of the issue with browning and leaf spots - this could be due to pH extremes or fluctuations, so it may progress until the new meter arrives. -Plants are in VERY different stages of growth! Plant A was moved to the bucket because it outgrew the aeroponics setup, while others aren't even an inch in height (and may not survive). We may have to modify our plan (maybe clone plant A and use those clones to keep everyone a similar size?) if this trend continues or if the small plants don't survive.