Lowlife Auto AK47...Nute Burn?

First of all here is a link to my journal just to give you idea what I'm using and working with. https://www.rollitup.org/aerogardeners/378790-g-first-grow-lowlife-auto.html

I was gone for 24 hours last Saturday. In that time my PH dropped to 5.1 and when I returned home there were some brown spots and some of the leaves look a little discolored. I got the PH back up to around 5.6-5.8. My question do you think this is a PH problem, nute burn, or something esle? I have been mointoring my PH levels daily. I've been keeping them between 5.6-5.8. I don't have a PPM meter but that should be in the next couple of days.

I have been using Advanced Nutrients Micro, Grow, and Bloom.
I started my nute schdeule two weeks ago.
First two weeks I just used PH'd adjusted water.
Third week I added 1.2ml Micro, Grow, and Bloom
Fourth week I added 1.7ml Micro, Grow, and Bloom


This is what they look like as of yesterday...

If the ph drops in hydro, that usually means your mix is a bit too strong, in most cases. Try diluting your mix with ph adjusted water, and raise the ppm when the plant reaches a size that can handle it!

Thanks a lot dudeoflife for the quick response. I just flushed about a little less than a half gallon out of my aerogarden and replenished with a little less than a half gallon of ph adjusted water. Hopefully that will work...I'll report back later on.