Diagnostic Help Needed!! (Pics & Info)

Ok these are 2 seperate plants both in the same grow room with temp between 73F and 78F and humidity runs between 30% to 40%. They are in soil with PH of 6.5 and are in end of veg stage, I'll be putting them into flower probably next week.

I let them dry out between waterings (usually 2-3 days). They have had about 2-3 weak nute feedings in the last 2 weeks, I hate to admit it but I used a Miracle Grow general houseplant feed. I have Tiger Bloom available for flowering but stores are really scarce on fertilizers this time of year so I settled for MG for veg.

I've looked at all the plant abuse charts and it seems like overfeeding and underfeeding cause similar symptoms for the plant with the claw leaves. Notice how it is yellowing on the outside of the leaves as well. The yellowing is not on all the leaves just a handful.

The second plant has the purple/reddish cast to the underside of the leaves. It also has the same color streaks on main cola and side branches. Photasium (sp) deficency?

I would really appriecate some expert advice, this is my first grow and I need help.

purpling comes from cold conditions. its nothing to worry about really... but when you water, aim for room temp on the water to reduce shock. MG is horrible for cannabis. if you must use MG, get one of those tree and shrub spikes, break off a 1/4" nug, and dissolve in water. feed only with every 2nd or 3rd watering. soil is very forgiving. you may also want to do a flush before hand.. a couple heavy waterings (as long as your soil is well aerated) will do the job. if you have any salt buildup, its detrimental to growth. i also highly recommend adding micorhizzae to the mix. it will work wonders. you can get a bottle of chappys power organics from plantitearth.com for about 15 bucks. worth its weight in gold.

I have 4 plants in the same room, 2 are fine and the other 2 are the plants in the pics. If the purple color was the tempature wouldn't it be effecting all the plants or is it possible for one to just be picky?

some plants like cold more than others. ive grown ICE that didnt purple even a tiny bit, but 5 other strains did. plants (especially grown from seed) vary individually. ive never seen P defic cause purpling though... and MG has a high enough PK to not cause a def. anyhow, try out what i said and get back with me. feel free to pm as well

yeah for the most part your plants look pretty healthy the drooping ive noticed isnt to drastic. mine do the same thing and when i turn my space heater on the perk right back up. so im with scias on this one. its probably a low temp.

Well hell I'll give it a go it's easy enough to get my room up to 80 degrees. In fact my grow room wants to stay hot - It used to spike to 86 before I put fans in and the plants were doing ok then, so hopefully your right.

I'll try for 80 degrees F in the room - I don't want to get hotter than that right? I've heard 75 is best.

What about the yellow edges on the first plant though? It's a different plant than the one with the purple undersides.

honestly im not sure, but the yellowing on your plants doesnt seem to be to bad. since you water every 2-3 days i imagine it couldnt be over watering. maybe a nitrogen or phosforus diffiency . possibly even a ph imbalance. at any rate it seems to be a minor problem i wouldnt loose any sleep over it! about the temp though they say 70-78 is optimal but to tell you the truth i keep mine at about 65f and when i turn that space heater on it shoots up to 80f. the growth is equal at both temps but they look healthier when they are at 80f.