RO water + no calmag = problems down the road.
Good for you for spotting (haha get it? spotting! ) them sooner rather than later.
That was most likely your porblem then!
stinkyattic Reviewed by stinkyattic on . Spotting on lower leaves? Setup: Simple Ebb & Flow PH ~ 6.0 Plant ~ 3.5 weeks from seed. Spotting on the lower leaves and slowly traveling up the plant. I thought MG def at first, but now I'm not so sure. Ideas? Rating: 5