Leaves turning wierd colours and I don't know why!

[HoneyBunch]

This is my first grow, using autoflowers under 540 actual wats in a 4.9x4.9 tent. In Biobizz light mix soil. Grow is just over 2 weeks old and they started shwing browning leaves at the end of the first week and over the last few days more and more of the plants have leaves showing problems. They had their first feeding of biobizz grow 2 days ago as biobizz says to wait 2 weeks before feeding.

I am using tap water (hard water area) and I have a wall mounted fan and a carbon extraction kit. I was having issues with ambient heat reaching up to 35c, however after moving the tent to a different space, I finally have consistent temps of 26-28c and humidity of around 50%.

I really can't figure out the issue on the leaves, I have checked for bugs and it isn't that. I have given them their first feeding and that hasn't helped. I could use some experienced advice.

 

[Kepp89]

I’m not too knowledgeable yet but it appears over watered and the droop seems to have caused the bottom leaves to be resting on wet soil which is no good. Or you use a sprayer to water and the spray got on the leaves during lights on which burned the leaves. The water droplets are like a magnifying glass and the light is intensified through it and burns the leaf.

But also a plant that young shouldn’t need nutes I don’t think. So maybe it’s simply nutrient burn but the droop screams drowning (overwatering). All I’ve seen is calmag being needed for people with particular types of water. At least that’s what I gather so far.

 

[The Jewels]

If your water is hard , it is probably chock-full of cal AND mag, I wouldn't be adding any of that.

LED is not point source illumination- so not light burned by water.

You said the problem started before you fertilizer'd it.
What kind of soil are you using ?