1st time grow as a trial run while I'm waiting on the seeds to come

[Doctor Herbert]

I got a freebie of the sweet deep grapefruit ...
I'm running it after my current grow.

I can't see any yellow in your pics, but I'm using a phone so I can't enlarge it. But hey, at least you did your homework and asked questions before you started. I have to give u some Rep for that my friend

Thanks!. it's not anything to be concerned about I guess. They've been like that for a while now (a month) and the plants are growing rapidly. Just to test my theory, I am building a "homebox" tonight complete with the lamp, 2 ventilators, tubing, mylar, etc. I'll post pics once I'm done. If it's the temp that's causing the yellowing, once they're in the box and receiving the heat from the lamp, it'll be all good.

I'm a bit concerned about the size of the pots I have them in. Do you know if they're okay? I can't remember what size they are.

Is this your first grow as well?