Someone check this out!! PICS shown

So my plants will be 3 weeks on Saturday and for the most part they look great. They were under a MH for the first week, then the ballast broke, so now they are under 2 t8 shop lights with two on the sides for added help. They are grown in MG organic potting soil, so they did have nutrients in it, which I believe is what slowed the growth a little bit. I don't water too much, I noticed one of the plants leaves drooping a little bit, I watered a little bit and she was fine. Now my question is the discoloring on only a couple of the leaves on the ends. It's not on all of them, and a couple of days ago I watered them with plant food, another MG product for indoor plants, but in a very diluted solution. (I want to start slow, then work my way up). I want to make sure it's some type of nutrient deficiency or ph or something. PH is around 6.75. So the third plant that started looks awesome, but has a purple stem and purple veins. The plant is supposed to produce purple buds and leaves, but I just want to make sure it's that and not something else. Here are the pics.

are these signs of a mg deficiency???

I think you worry 2 much!!

Straight water next time then go for it!!

JUST SAYIN

haha i know i'm paranoid, I see all of these other posts of these nutrient deficient plants and I want to avoid that at all costs. So next time straight water, then go for what? diluted fertilizer next time?? Please do elaborate and thanks for the reply. Feels like no ones on these forums sometimes cause everyones :stoned: lol :thumbsup:

like everything else, plant leaves aren't perfect :wtf: ... slight browning of the tips is usually a sign of over-fertilizing ... personally, I grow my plants, with SLIGHT tip burning, then I know she's getting enough ... most everybody overfertilizes, and overwaters ... just leave the plant alone, between feedings ... I recommend half-strength fertilizer, ONCE per week, you can always add more if needed, but it's a lot harder to fix over-feeding ... it's a WEED :smokin:

One thing to note.. how close are the lights?
My last lot started canoeing slightly with raised edges.. it was high PH as the major cause, however even a couple weeks after that was sorted, I realised I also had my lights a bit close.
Looks more like heat than nutes. wouldn't the entire tip be going brown instead of all around the edges? (see pic, took that just now, lights/temps are sweet)
From what I've read, and I'm only 2 grows deep, they were trying to get rid of the heat.
Maybe something to look at.
If thats not the case.. at least I tried :thumbsup:

Good luck :rastasmoke: