First grow, some problems

[Vlady]

Hi, I having some problems on my first grow, the new leaf are pale green and the bottom leaf are getting brown on the tip reaching all the leaf after some days.

They seem greener in the photos because of the light.

I am using a 250W MH lamp.
The temps with the lamp on is 24C (75 Fahrenheit) and when off 18C (64 Fahrenheit).
I am using bottled water it has 6.0 PH I tested.
Didn't use nutrition yet, the soil is BIOBIZZ - LIGHT-MIX.
I have a decent ventilation intake and outtake.
The seeds are all different types of autos.

Any ideas are welcome I have read some threads and still don't know what it can be.
I will post some photos of them.

 

[Vlady]

Re: First grow, some problems.

Is it possible that it is a sulfur problem? I read that "First signs of a Sulfur deficiency are pale young leaves, in soil sulfur gets locked out in soil on 2.0-5.5 pH levels", if I raise my pH levels should that alone fix my problem with my slow growth and bottom leafs turning yellow?