Please Help! What is wrong with my plants? Pictures Included.

My plants are about 5 weeks old and under a 1000 watt light. There is adequate spacing between the plants and light and i am currently in the Veg cycle. I am growing indoors and have a ventilation system and fans running. My humidity is around 30% or less and I am growing in dirt. The last couple weeks my plant growth slowed, leaves started yellowing, and brown spots started to appear on the leaves. It started on the fan leaves and is now mixed among the plant. Some leaves are partially deformed and growth has slowed to almost a stop. I tried doing a flush and the plants started growing again but shortly after began to stall again. I am thinking it is a Manganese deficiency...am i right? Is it something else?

Please help me!!!

The leaves with damage on one side are displaying a symptom of Phosphorus deficiency. The yellowish new growth looks like it may be a symptom of cold nights. Check the soil pH if you haven't yet.

i have a thermometer set up that shows me the high and lows. i have been checking it daily and the lowest it gets is around 63 degrees F. Currently i am using Supernatural Brand nutrients. I am using their Grow Terra and their micronutrient blend. Should i add extra phosphorus on top of that or maybe mix the nutrients a little stronger?

Check your water PH. Make sure it is between 6.5 -6.8. You should be following the guides on the bottles of nutes. Don't give anymore. Make sure your PH is correct because if it is not you may just be locking on nutes and that is why your plant is suffering.

Looks like magnesium deficiency if you ask me. but PH first!

phosphorus def could be caused by a ph lock up. 35% hum I would up that to high 40s if you could. how often do you water? droopy plant could be over watering.
weird looking curling leaves points to a ph issue, SO i WOULD LOOK INTO YOUR PH

Ya I never go over what they say on the bottle but i do usually do less. it says you can do 1 to 1.5 tsp per gallon so i usually do the 1 tsp just to be safe because those are their maximums. i have also heard its good to do half strength because then they suck up more water along with nutrients. has anyone tried that and gotten any results? Good or bad?

ok thanks everyone! I will check PH tomorrow and get back to you all

I wouldnt wait till tomorrow lol

I just looked up Supernatural. They say you can double of what it says to use. Peace, jethead

So my ph is at 6.5 in the soil so it isn't a ph problem and the plants are getting even worse. what can i do to prevent their death?

Could be from overwatering. Do you let the soil dry out between waterings? What PH do you feed/water them?