Leaves of my plants started to turn yellow, almost white on bottom branches. Plants are 5 weeks old grown from seed and currently vegetating. Is this a sign that my plants lack nitrogen? Should I start fertilizing them? I don't use any ventilating fan so could it be that humidity build up can cause this?
I water them every 3 days with pure water. Temperature is about 74 F and soil pH about 7.

Please tell me if you know what's wrong.
daylight Reviewed by daylight on . Yellow lower leaves - 5 week old plants. Please help! Leaves of my plants started to turn yellow, almost white on bottom branches. Plants are 5 weeks old grown from seed and currently vegetating. Is this a sign that my plants lack nitrogen? Should I start fertilizing them? I don't use any ventilating fan so could it be that humidity build up can cause this? I water them every 3 days with pure water. Temperature is about 74 F and soil pH about 7. Please tell me if you know what's wrong. Rating: 5