Help with my leaves?

I know the plant looks bad. It is on the come back. Every day there are new leaves coming out the top. But a lot of the leaves look like this. Please help me diagnose this.

400w Hps
76-79F day
68F night
Right now it is just getting distilled water

Hey

Give us some more info:

For that temp is your light aircooled?
What ventilation are you using?
Humidity?
Do you PH your water?
What's your growing medium?
How often are you watering?
How old/big is your plant and it's container?

are all you plants affected? Have that yellowing at the end of leaves?

-Light is not aircooled.
-4inch 80CFM intake fan
-8inch 500CFM vent fan
-Humidity 31%-38% (I have a humidifier in the cabinet)
-Yes I do pH my water, but right now using distilled to limit it down to probable cause (7.0)
-Some old foxfarm soil
-It has been rather wet due to flushing it because I thought it was burn. I have a watering gauge that says 1(dry)-4(wet). Right now it is between 2 and 3. I am not sure where I should keep it?
-Im going to try and let it dry out between 1 and 2 before I water next.
-Plant is 7 months old (it was a mother used by another grower for just clones) About 3 feet tall. Pot is 10 1/2 inches across by 8 1/2 tall.

Only one plant. I have noticed some new leaves grow out and then yellow at the end. The leaves have large veins as you can see. I think it is overwatering, but I am not sure.

up please!

You need to be using nutes thats your prob man.

Are you sure its not nute burn??

up please.

Psy or Air?

go buy some nutes and use them at 1/2 str Its not nute burn its nute defecencie. Use GROW ferts for veg and Bloom and Blossom for Budding

YES! Your plants to be very low on nutes!

I went out and bought some Sensi Grow Part A and B by Advance Nutrients. The leaves look like they are already improving a lot.

Thanks Guys