Leaf discoloration on young plant?

Hey guys, marijuana growing newbie here, this is my first plant that I'm in the midst of growing. She is about 5 weeks old, and she lives in a cute little 32x32x64 grow tent with a little fan and a Mars Hydro LED located about 4 feet above. Every other day or every third day I give her some water and feed her a bit of Botanicare Pure Blend Pro. A couple of days ago I picked up and added some hydro-guard and a bit of rhizo blast to the routine because I was told these are good things for my plant's roots in particular.

Last week, I noticed that one of the oldest leaves had a hint of brownish/orange discoloration. A couple days later, I noticed a second leaf closer to the top of my young plant had the same discoloration. The top leaf is getting progressively worse each day, and I'm wondering if I might have a PH imbalance? Any ideas on how I may nurse my plant back to health?

I'm having a difficult time diagnosing it online, I appreciate any input the community may have!

Get a pic of the whole plant. Might be useful now and later if it progresses. Doesn't look like a nutrient or watering problem. If it progresses you will have a picture to compare it too. If it doesn't get worse your good.
The little leaf almost has the look of a leaf that has been touching the soil at the base of the plant. I wouldn't worry yet. I think the big leaf has damage from being crushed accidentally and you would not see the damage for several days and then when the dryness appeared it looked like a problem was developing. Just a guess.

What is your ppm? Looks like it may be too high, but pic of whole plant needed.

Ok here are a couple pictures I took just now, it seems to be only two small areas/leaves that are affected thus far.

I don't know the exact PPM, however I'm using about an 1/8 tsp. of Pure Blend Pro and about 4 TBSP of water. Four days ago she got her first 1/16 tsp. of hydro-guard and rhizo blast each, in addition to the 1/8 tsp. of Pure Blend and 4 TBSP of water. Two days ago since I was nervous about the two leaves, I chose to give her only 4 TBSP of water and 1/16th hydro-guard.

LittleMeows said:

Ok here are a couple pictures I took just now, it seems to be only two small areas/leaves that are affected thus far.

I don't know the exact PPM, however I'm using about an 1/8 tsp. of Pure Blend Pro and about 4 TBSP of water. Four days ago she got her first 1/16 tsp. of hydro-guard and rhizo blast each, in addition to the 1/8 tsp. of Pure Blend and 4 TBSP of water. Two days ago since I was nervous about the two leaves, I chose to give her only 4 TBSP of water and 1/16th hydro-guard.

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Thanks for the pics, my opinion is the same as above as far as the leaf damage.