Auto haze plant may be sick :(

So I managed to get a cheap aerogarden, and started a Royal Queen auto haze seed about 3 1/2 weeks ago in it. So far everything has been going very smoothly, until today I noticed some of the lower fan leaves have developed tiny brown spots. I'm using Advanced Micro, Grow, Bloom PH perfect nutes, and distilled water. Also attached an airstone. Other than the brown spots, the plant seems to be very healthy and is growing at a very quick rate. Anyway will attach some pictures to see if anyone has any idea of what these brown spots are. (sorry for pic quality, got as close as I could without touching plant.

Im not sure what that is. I do know its happening to mine also. Doesnt look as bad as that but its there. It also happend on my last (1st) grow in my AG3, it didnt start as soon last time though and still produced some nice smoke.

The rest of the plant is growing fine, this stuff seems to be only happening to the older leaves. Will see what happens

Ive heard the lower leaves discolor and "dye off" as the plant grows because its pulling the nutes from there to promote new growth.

samething is happening to my plants any fixes for this ???

I have a home built aerogarden, and also used advanced nutrients. I had similar brown spots that developed into something worse. From what I've concluded, it is either a Calcium deficiency or nutrient lock out from salts. I've since been supplementing with Cal Mag but mine were too far along before I figured it out. Best of luck.

phosphorous deficient i think? Hygrozime!

Cal-mag deficiency.......... add more cal-mag to nutes, other wise flush your plant it could be nute lockout but seems to young for nute lockout.

Looks like the very beginning of manganese or potassium deficiency. watch the rest of the leaf if it starts to yellow from the inside out toward the tips its manganese, if it starts to yellow from the outside in starting from the tips its potassium.