2 weeks into flowering and some middle and lower leaves are turning yellow and have brown spots.
Soil
RO Water: PH is 6.5
1000 watt light: 20 inches away
temp: 28C between light and top of plant
Pics are always a good way to show us what you are talking about. Less left to guess.
Where on the plant are the bad leaves? Uppermost leaves will be the ones to exhibit any signs of stress from heat. And 20" sounds a bit too close to ME for a 1k lamp. I use 400w lamps, and they are about 18 to 24" from the tops,
Second, if all the damage(?) is on the lowermost fans, then in all likelihood it just normal shedding of leaves. They WILL yellow, wither, and die during the grow. (Just not all at once!!) The closer you get to harvest, the more "autumn-like" and yellow they get if you've done your job.
I'm right there with ya at couple weeks in, and at this point is typically where things have always gone south for me. Right now, My girls are lacking P a bit, but so far.......we're golden
If you have a way to check pH, the run-off is what will tell you what is going on inside. So far, looks like you have about the same conditions I have. My water stars out at 7.2, I'll add whatever I need to the water, and pH it to about 6.5. The soil, any nutes collected in there etc will bring my run-off down to about 5.8. Get the pH down pat. If you KNOW your pH is right, then you won't have to second guess about things. Deficiencies and pH lockout look a whole lot alike to us lay folk.
