Deficiency? What kind?

One of my plants has some greyish colored spots between veins on a few of the lower leaves. I noticed it the day after changing the nutrient solution, only thing I've done differently was add Sensazyme to the mixture.

I'm running at pH of 5.8 consistently, TDS is 550. Daytime temp is between 80-85F and 68-74F at night. Humidity is between 55-60% and root zone temp is 72F.

Using Technaflora nutrients at a 1/4 rate as plants are still young.
Plant is wonderfully healthy otherwise, aside from a slight damping off problem about a week ago which it has recovered from (slight brown area on stem still).

Anyone know what this discoloration is?

Here's a chart that might help

bigrake said:

Here's a chart that might help View attachment 2408490

Click to expand...

Hmm... Maganese or Potassium perhaps? Chart is a little low res so it's hard to get a good idea but it is very helpful, thank you for this!

interesting.............grey, you say. no red/purple stems..........had damping...........
systemic fungus? i don't know. grey is a new one on me

whole plant pic, perhaps?

I will put one up tomorrow when the lights go back on, I would have to take the pic under a green light right now since I have them on 12/12 to sex and don't want to disrupt light cycle with a flash. Its growing awesome otherwise, stems and everything but two leaves is colored correctly, but yeah the spots are grey, mottled brown in the center, almost blue-ish around the edges of the spots. I'll get a full plant pic up ASAP.

Alright so this morning the spots have gotten more yellow than anything, still look as strange?