My plant by wilted in 6 hours
 

I am running a individual bucket system with aquarium pumps no reservoir I have 1000 W mh and I'm feedind foxfarm
I had beautiful 3 foot tall tomato plants I'm on the fourth week feeding schedule and second water changes and for three days everything was great business as usual then I turn my light of and 6 hours later one of my babies has completely wilted and a second is yelling and curling I'm new to hydro due to the por gardening season and my area this year I had been very impressed with my results to this point my water is very high in iron and I've been maintaining a 6.9 Ph any help or advice would be greatly appreciated