Red/purple stems w/ many more problems(PICS)

this is being grown indoor in a DWC system 400 watt MH light / 2 20 watt daylight cfls. there is a very mild 1/8th strength solution of miracle grow all purpose plant food

i don't understand what is going on with my only 2 plants are these red/purple stems bad. what is the white spot on plant #1, i'll let the pictures speak for themselves.

flush, and switch miracle grow with a recommended nute, that stuff supposivly is horrible for pot

the purple stems are fine....as for the white spot...i have no idea!

all good spot spot prob rubs off and buy advanced nutrients and use 300 ppm till a foot tall then to 600 ppm till 2 feet then 800 ppm till 4th week into bud then 1200 ppm till wekk 6 then flush for 2 weeks

thanks guys

alright guys i cleaned and flushed the res and the plant looks better.

the plant that was bent over died so i only have 1 plant left good thing its just some bag seed



also. is it alright for me to keep my plant with the reflective disc thingy over it, or should i just leave it off.

i read somewhere that it was good to cover your plants to stop the light getting into the res causing algae