One leaf at a time yellowing, then blackening

A week ago I notice a couple leafs were starting to yellow outward to inward, then a couple more leafs, now the older yellowed ones are starting to turn black in the middle of the leaf. Any suggestions?

Could you tell us more about the grow? pH? lighting? nutrients & schedule? watering schedule? etc...

ph levels have been around 7. This is a soil grow with MG moisture control, I water about every other day, sometimes on the 3rd day. I have foil over the top of the soil to help reflect light upwards. I use fox farm grow big for every other watering. The room usually stays about 70 degrees with a 600 watt metal halide with a lumatek digital ballast outside the room and a sunleaves artic hood.

gnsonsllc said:

ph levels have been around 7. This is a soil grow with MG moisture control, I water about every other day, sometimes on the 3rd day. I have foil over the top of the soil to help reflect light upwards. I use fox farm grow big for every other watering. The room usually stays about 70 degrees with a 600 watt metal halide with a lumatek digital ballast outside the room and a sunleaves artic hood.

Click to expand...

Ph is a bit high...6.2 - 6.8 for soil grow...I'm not a MG fan, its usually pre-nuted/moisture cont., easy to OD on nute/water , hard to come down...Mylar or flat white paint instead of foil.... I'd fix the PH 1st.. luck..

room is painted white, i just use foil over the soil to help reflect upwards on the lower leafs, plus it helps keep the light from drying up the soil so fast. I just looked it up on the plant problems in GrowFAQ. I have a nitrogen def. I will be getting some stuff tomorrow to help take care of it. Plants have actually been doing great, they did seem to be stunted for a while, but now the leaves are getting huge and the whole plant is getting more and more bushy.

This is a medi bud straing of marijuana-seeds.nl

Looks a lot like the THC Bomb I got going on right now