SOIL Leaf spots, please help

[ChrissyJ]

Hi all, hope everyone is well. Just had a question about random spots appearing on my girls. first time grow so I get paranoid about any thing that might be wrong. Growing three different plants one Autoflower Indica one White widow and one random bag seed. all are showing these random spots that start of kinda pale green/shiny then turn necrotic. Symptoms started appearing about a week ago. Indoor grow Soil is Scotts pure organic mix at a Ph of 6.5/6.7 and contains 3 months of NPK Also had a small fungus gnat problem in at the beginning but treated with Bti and hasn't been a problem since. No other pests, Iv'e been searching. Currently 6 weeks from seed and about to switch to flowering in a week or so. Growing in a bathroom for higher humidity but not sure exactly what the humidity is. Under LED 18hr/ 6 hrs sitting 50cm 20inch above canopy. Room temp 26C 78.8F also has small oscillating fan. Think it might be a deficiency maybe but I honestly don't know. If anyone could help it would be much appreciated Cheers C.J

[D.A.A.S.69]

GoodMorning CrissyJ, fungus gnats, are pretty easy to handle, with just yellow sticky pads, and by not keeping your soil at the top, to wet.
But I think you are going to have later problems with the Scotts time release soil, it's not good for growing MJ.
GoodLuck.