How old are your plants? I had the same problem with my Apollo 13 plants after a transplant. I gave them a half dose of nutes and it helped, but they were still this olive drab green/yellow color. I dosed them with a normal dosage and they perked up and took off. They haven't stopped growing since.After noticing the plants loosing their green colour, Ive feed them some organic grow nutes, after 2 feeds the bottoms are still not darkening up, should i up the dosage? dont want to burn em
Regarding nitrogen def: I'm gonna have to go ahead and disagree with you that a nitrogen def will show on both lower and upper growth. It might, but only if the deficiency is fairly advanced in stage. As you probably know, N def starts at the lowest growth and works its way up the plant starting with the lowest main fan leaves and working up from there and then it starts again on each main branch again working its way up from the bottom.I would bet that you are haveing low soil PH. That would be my first guess after you fed them already. You should know the ph of your soil?? Is it over 5.7 - 5.8. Nitrogen lockout starts at about 5.7 in soil. I had this happen and added 2 tablespoons soil sweetener (hydrated Lime...the white powder stuff that looks like blow but dont snort it...hehe ok bad joke) Anyway....2 -3 tablespoons in a gallon of water will bring the soil ph up to 6.3 if its down below 5.7. At least it did for me...and then my plants were able to take up nitrogen again. I am assuming that not only the bottom leaves are light. If its nitrogen def then it will be the upper leaves also. A few yellow lower leaves is normal for plants when healthy sometimes.
1.Check your soil ph
2. take picture and post it
3. Dont feed anything untill the soil has been checked
Just my 2 cents
Grasshopper