Mystery Diagnosis!! Yellowing leafs w/ brown splotches

This just developed over the past couple days after using Botanicare's Liquid Karma. Followed their recommended dosage of 1 tsp/gal for seedlings, along with 1/4 strength FoxFarm Grow Big. Checked PH, its was around 6.0, TDS around 200ppm. Using nutrient-less potting soil in a 1L starting pot. Regular veg cycle 18/6, room temp stays around 75F. I give my plants a little water (1 oz or less) everyday and every 3rd day feed it 2 oz of the 1 tsp/gal Liquid Karma, and 1/4 strength Grow Big and 1 oz of bottled water. Will be upping the Grow big amount to 1/2 strength by next week.

Both 1st true leaves are showing dark brownish splotches (necrosis) and yellowing near the tips and ridges of leaves first, this pattern is working it way down to the stem. First the cotyledons yellowed now these. Plant hasn't grown much since this started. After this problem started, I flushed plant with slightly basic (7.5 PH) tap water and noticed the soil was badly compacted (de-compacted it during flush).

Any help or tips would be greatly appreciated. +Rep for helping out!!! Thanks for reading!

Post a few pics.....

DaBong said:

Post a few pics

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Well a couple weeks later of intensive plant care, I mean everyday foliage spraying with full strength FoxFarm Grow Big, it recovered nicely. I had to cut off half of the first true leaves where the necrosis and yellowing took hold; none of the upper leaves succumbed to necrosis thereafter. Also, what I think helped a lot was transplanting it into a much larger pot. This leads me to believe this plant's problem was due in part to root boundedness and not enough nutrients (mainly nitrogen).

Planted finally died, but I figured out what the cause was... I was upping the pH to 6.5 with sodium bicarbonate every time i fed the plant Fox Farms Grow Big solution. With all the sodium bicarbonate accumulating in the soil, it caused the pH of the soil to become very basic. I tested the run off and it measured 8.0+ (using GH pH test kit, it doesn't go higher than 8 pH). I didn't catch it in time but this experience has taught me a lot. Next time I will be upping the pH only when the run off reads lower than 5.5 pH. Testing pH for the feed solution and run off is a lot of work so maybe I'll just switch to a hydro grow. Time will tell... Thanks for reading, Hope this helps your soil grows...