Not Sure Which Deficiency : Discolored Droopy Leaves

Hey guys, I have a blue himalaya diesel autoflower thats on its 23rd day. In the last week the leaves have started to show a lighter color on the leaves and it seems to be getting worse. You can see in the pics whats going on with the leaves, its hard for me to explain. It has been in a 2 gal smart pot with FFOF its whole life. I don't water that often because the medium seems to be holding water. Today is a day I will be watering but I am going to wait to hear what you guys have to say because I am thinking I will be going to buy some nutes. It hasn't had anything but pH'ed water so far. I might also add that its being grown under an LED. I appreciate any help you guys can give me. Thanks RIU

What are you PH-ing the water with? I'm under the assumption, (not a good place to be by the way), that you don't need to PH FFOF since it's buffered, so PH-ing might be the problem. Maybe your strain isn't a big fan of PH swings or maybe it's what you're using to adjust the PH with. Also how light is that pot? I ask this cause the plant looks a little over watered in pictures 1 and 3, which can fuck with your roots causing all kinds of problems. And if you're using LED's you probably need to add some more Perlite to FFOF to get proper drainage/aeration. Anyway just some thoughts, your problems remind me of what my TD's used to do if I tried to PH them and/or over water them. So Good Luck, and I hope you figure it out.

My tap water seems to be at an acceptable pH range, I have pH up and down though. The pot is definitely not over watered because I barely water it. I added some fresh soil to the top of the smart pot yesterday and I think its a shadow making it look wet. I was going to add some epsom salts to my watering today, does this look like a mg deficiency?

The problem has moved from the bottom towards the newer growth at the top. Fan leaves are curled down and have that burned look. I added 1/2 teaspoon of epsom salts for every quart of water that I gave them yesterday. We will see what happens but this one has me worried

bump... any suggestions

Do the leafs keep dieing?
I had a plant where it was getting something like that and it got droppy and fan leaves died.

but really not sure...
test the ph of the soil ?