Can you do pretty much everything well...but.....

still end up with runty, poor, streesed looking plants ? genetics ??

yes.... although i would say that it is the least common reason for bad plants....

Why do some of my plants look fine...but others look awfull ?

could be due to all kinds of things... post up some pics with more info about your grow...

I will update the journal later...but heres the real bad looking one, im not to fussed as im not going to bother flowering so didnt transplant...she looked poor at a few days old and just continued to grow that way.....some of my other plants dont look 100% but this one looked really bad.....

What light are you using?

the first 3 weeks a 250 watt CFL , now a 600 watt hps, heat has never been a issue, never higher than 82

The way the leaves are veining I would say lack of Magnesium, try a few tsp of epsom salt when you water and see if it changes. If MG. is locked out only a flush to raise the ph will help.

your right, i thought it was low ph, my fault being lazy, iv been lucky the others seem ok, i will cull her later...i think shes to far gone