Thanks for the reply; some more information:
Seeds: Jack Herer autoflower from ILGM
Soil is a seed & cutting germination mix, I’ll attach a pic below
Vessels: 25cm plastic pots (?7-10L)
PH 6.8-7.0 going in, run off was PH 5.5 (please note that I have since flushed both pots with about 30L each PH of 6.9 to try raise the ph, still run off is only nudging PH 6.05-6.1)
PPM/TDS I do not have a reader so cannot answer sorry
450W led light (180W power, model number GL-NM-3T-450)
Temp range 70-79°F
Humidity RH 42-62
Carbon filter with 4inch inline ventilation fan speed control with separate 4 inch inline intake fan.
Have just added dehumidifier as entering into flower
Am currently at day 36 after placing seeds into water for germination.
Hope this helps. As I’ve mentioned I’ve given both plants a good flush with pH water around 6.9 and can only get the ph in run off to about 6.1 max. I’ve actually tried last night and this morning with the same result, even with 30L running through each pot.
Feeding I have been using general hydroponics micro and bloom nutrients with professors nutrients go green cal/mag see pic.
I have been feeding about every 2 -3 days when the soil is dry giving about 2ml cal/mag, 2ml micro and 4ml bloom in 5L water (divided between both plants) ph’d to about 6.8.
Beginning of last week I upped nutrients to 3ml micro and 6ml bloom keeping cal/mag at 2ml. Noticed faint burnt tips on a number of leaves on both plants. So next feed was just pH water 2 days after last nutrient feed, then yesterday (2 days after water) I noticed the rusty spots on a number of leaves, however these are only on one plant at the moment.
It is my first attempt at growing and was really enjoying it but am stumped at what to do to fix this issue. Any help would be great.