Leaves curling up, purple in margins

Hey guys, so 3 plants growing in coco, GH flora series plus Calmag, 3 weeks into flowering and like the title says I've got leaves curling upwards and purpling in the margins. Mostly on the upper fan leaves and smaller fan leaves towards the middle of the plants. I'm only noticing it on 2 out of 3 plants, and majoritively on 1 plant. Coincidentally, on the same plant I was noticing a calcium deficiency so I fed them the same amount of nutrients, but I added about 20% more calmag than normal and this happened overnight. Tempso with the hps on haven't gotten over 82 degrees, with lights off haven't gone under 65. Any ideas folks?

The " purpling " is from lower night temps ( you mentioned at least 65 degree ) , and or a latent trait from the strain.

As far as the curl , wouldnt read to much into it as long as temps are controlled or leaves are not getting crispy or showing any other deficiency.

Looks like this

Preciate the quick reply man, I'll keep an eye on it and try not to worry

NotThaddeus said:

Preciate the quick reply man, I'll keep an eye on it and try not to worry

Click to expand...

They're looking good

1 of the 3 is budding tremendously quicker than the other 2 as well. They are all different strains though, so I'm assuming that is all it is!

So just to follow up, the darkening of the leaves I'm noticing is not the natural purpling of the leaves. Nute burn maybe?