hey bozy,, she looks good... red is not to much of a problem if any when it is on the leaf stem.. but when it is on the main stalk, it is worth watching very very closley... it can often mean a NITROGEN deficiency.... or some ph issues..

Like purple said there are strains that get the red stem thing going...

your plants look good... if you see the red on the main stalk... take more pics and let us see.. if you were having a major nut deficiency, it would show in your leaves..