Not sure

Not sure what's going on with my plant. Nutrient burn or too close to the light?

I've been watering her with 6.5 ph water, tested it myself. Planted her from seedling in roots organic "original" soil, she's 1 week and half. She's placed in a 1 gallon smart pot.

Everything seemed fine then the bottom leaves turned yellow and top leaves withered. Nutrient burn? But I don't add nutrients. I just let the soil do the work.

Any ideas ? If they die oh well, but I need to know what caused it so I won't repeat the mistake.

I have them in a indoor tent
4 x 2 x 6 with two 4' T5 strip light from sunblaze. I have them 5" away from the plant. Hanging above.

Temperature is between 70-75. Humidity level at 40.

I have 240 cfm blowing in and 240 cfm blowing out and 1 tiny fan on the ground circulating air.

Thanks and sorry for the long ramble.

5" is too close for a young plant it doesn't have the roots a leaves to deal with it. The soil looks dry and in fabric pots you need to keep soil packed in the crack along the inside edge because the water will run down the side and create uneven moisture.

your RH is on the low side you need to increase that, also test the PH of the run off after watering, your soil maybe too acidic

Lift that light to 1.5-2ft at least, don't over water her either, just as bad as under watering. They're a weed so as long as you get water and light right she will be happy

AS above, looks like light bleaching, raise the lights to at least a foot or more and give them some seaweed supplement.