Paddys 1st Grow

Into week 6, biggest plant which seems a week or 2 ahead of others is paling a lot on bigger top leaves. Foliage under still green. Lights are a fair distance, all 3 on same feed no issues till now. Not sure if just the buds draining or not. Have started pk13/14. 2 smaller have some catching up to do. Hopefully home stretch, I wanted to be harvesting all together but don't think that be happening.