Need Help - Sudden limp and yellowish leaves

Hi. I am having problems with my baby. She suddenly has limp and yellowish leaves. She is about two weeks into the flowering 12/12 schedule. I water the plant based on a soil water/ph tester that probes about eight inches down into the soil. I wait until the soil is in the center of the green indicator for water level (before it gets into the red). I know it's not the most technical explanation, but you get what I mean. The leaves began to get yellowish so I thought maybe that I have put too much nutrient into the water, so I flushed it with about a gallon of water. There was an issue with mites prior to going into this grow box, but they were dealt with using an appropriate "pesticide".

Growing environment:
The pot is about 10 inches tall and about 12 inches across. The growing medium is not completely know as I was given this baby at about twenty four inches tall. It does have a decent mix of perilite and dark rich looking soil. I grow in a box that I constructed for a previous grow (4' H x 18 D x 19 W). There is a fin intake in the bottom left and a fan out on the top right. I use a 125w EzHydro 2700k bulb in the top and 21" florescent tubes in each corner (the purplish bulbs). The temperature is about 78 degrees all the time, I have not gotten tester for humidity yet. I do mist the plant a few times during it's light schedule. The temperature during lights out is usually about 73 degrees.

Not sure what else you might need to know to help, but any help is appreciated.

PH looks way outta whack, and they look over watered.What does your PH tester tell you?How often do you feed em?How big is the plant? Pot seems kinda small to me.ccb

You need to flush thoroughly and water less in the future, I also believe you have nutrient burn/lock. Buy a decent ph/tds/ppm meter then your problems should end.

Morning
Quit misting, check your PH and don't flush'em if it's outa whack, adjust slowly so the containers can dry out a bit.
Good luck

So at this point I should just let the soil dry up a bit, perform a ph test (I have a test kit with little shakers), and obviously change my nutrients?

Hey Mad
Anything new happaning with those girls ?

they do look very over watered...do not worry however, i had this same problem stop watering it, if your tester is broken you will be delivering your plants the wrong results, and as far as pesticide, cant be good for the weed