help please plants not looking so good pics

room is 6x6x6 mylar tent
using 400w mh horilux blue
temp between 70-79
humidity 45-55
hydro ph is 6.1 was a liitle low raised up water seems to be a little cloudy will change out tommorrow. and ppm was 500-600 but checked last week just took this photo tonight.
Not sure whats going on leafs are curling under and some are dry
also about 5 days ago i had a 1000watt hps in there thought i would up my lighting but enedded up they did not like it. took out and put 400 back in
also i have been dealing with spider mites but have a spray that im using every other day that has been helping

how fast did this all happen?

it has been like this for a few days i can post earlier pic

It seems as if your temps are good.

If Your PH is good.

Your lighting is sufficient.

Then maybe you over did it on the nutes.

Or you have an overly finicky strain.

guess not no pic here is my inside set up older pic

Your leaves don't even have tips anymore. I'm thinking the temps get too hot and the nutes are too hot as well.

Are you certain about the water PH?

i also keep a heater in the room cheap wall plug in cause it gets cold at night. can heater be causing ?

also added some cal/mag think mabey that could be the problem?

Bump help please