Blackening growth shoot

I posted this in my grow journal, but I'd like an answer before it's (possibly) too late.

Could anyone tell me what might be wrong with this branch? On my thread it was suggested it's fungus, and I thought it was some kind of micronute deficiency, but I'm still not quite sure.

im pretty sure its some sort of deficiency, look at types of deficincy pics to determine what u need

Shit, now all the branches are like that on Kalichakra. Apart from that, it's growing very well. Any ideas?

mag def hit it with some mag

You sure?

It's gotten worse. These pics are from a few days ago, by now about 3/4ths of the growing shoots are purple, stunted, twisted, and deformed. This is one of the worst things I have ever seen on a plant. I looked up magnesium deficiencies, and none of the pictures I saw were anything like this. Does nobody know what this is?

Bump for emergency

you can check here...
Nutrients PH Problems On Marijuana Plants Spots Symptoms That Appear
kinda looks like maybe phosphorus deficiency. I don't think it's mg I believe the tips would be curling up. Could also be a ph issue. Do you check your ph on a regular basis? Just thoughts. Hope it helps

feed them some fish emulsion and check
the ph or it might be some type of fungus!?!