Looking for help with my plants

Im growing in a 3x3 tent with a 600w mh lamp ~18 inches away from the biggest plant.
Im using fox farm ocean forest soil and watering about 2-3 a week.

I planted my seeds(barney farm's lsd) on June 18 after the taproot was long enough. I planted 5 and only 3 popped through the soil, and only two of them actually survived that (I think it is because i drowned them). Anyways only one actually grew normally which is the one in the pictures.

I recently found mites on one of my clones so i threw it away and sprayed insecticide spray on everything two days in a row and havent treated them for two days. I was thinking the curling of the leaves was just some stress from spraying the plants down to kill the mites, but when i saw them today they were exponentially worse than yesterday.

This plant is on its 4th week of veg.




Thank you!

Bump
Problem is getting worse now the leaves are crispy

first thing 18 inches is to close for such young plants back that light up...give it some time should recover...

Did you spray while lights on? You might have just burned your plants to a crisp. Just be gentle the next couple of weeks.

looks like to much Nitro

600w is too intense for seedlings! A few CFLs is more than enough to vegg plants.

I moved the light away, now it's more than two feet away from the tops.
Also im not giving any nutrients just ph'ed water.
I sprayed them with the lights off.