yellow leaves

I agree with my colleague, but these are not just the lower leaves, increase the food a little and that's it, there's no need to worry, everything is fine, it's better that he lacks food and pulls it out of the leaves when there is no more than to overdo it and create 100 more problems!

As they mature, it's normal to see lower leaves fading and dying as she forces the energy on where the most light goes and into her flowers. I see beautiful natural process in making, nothing to worry about!