Help?! Indoor organic soil AMS grow, yellowing leaves / purple stems

[voodoopoerk]

So This is my buddy's first grow box and he got this clone from someone, the age of the plant is unknown, as well as the exact strain other than that it's AMS fem. I'm using Jobes organic food and miracle grow organic soil. I've been having a minor gnat problem, I tried covering the soil with cloth to get rid of them, and i've been disturbing, removing and replacing the top few inches of soil every day. They didn't go away so I got some organic pesticide with pyrethins and neem oil extract, applied every 3 days and the gnats die down in numbers but then come back slowly. The yellow leaves and purple stem leads me to believe its a nitrogen deficiency, but I'm not sure if its actually that or thats a side effect of the gnats. What do you guys think? I'm not sure what to do at this point or if my plant is actually in trouble.

 

[voodoopoerk]

What Strain is it?
-Not sure exact strain other than its AMS Fem.
Is it Indica, Sativa or Hybrid? What percentages?
-^
How Many Plants?
-1 for now
Is it in Vegetative or Flowering Stage?
-Veg
If in Vegetative Stage... How Long?
-At least 3 weeks, buddy got it from someone so other than that age unknown.
Indoor or Outdoor?
-indoor
Soil or Hydro?
-soil
If Soil... What is in your Mix?
-Miracle Grow regular soil with Jobes organic food mix
If Soil... What Size Pot?
-Smaller couple gallon pot, going to transplant into 3-4g pot soon.
Size (Wattage) of Light? How Many?
-5 100 watt CFL's. 3 blue, 2 red
Is it Air Cooled?
-2 Comp fan exhaust
Temperature of Room/Cabinet?
-Averages 69-79
PH of Medium or Reservoir?
-Only have a cheap ph tester, but it looks to be between 6-6.5
Any Pests?
-Gnats, pesticide to counter, numbers dwindling but still present.
How Often are you Watering?
-Whenever needed, normally every 2-3 days.
Type and Strength of Fertilizers used?
-2% N, 6% P, 4%K
Size or Square Footage of Room?
-Rather small first box, 2x1x3

 

[pizzajedi]

well im a new grower, but ive been doing a lot of research on this recently as i had similar problems that im in the process of remedying so ill try to help as best i can... im sure a more experienced grower can chime in and make it clearer than i can. anyhow, the purple stems could be genetics. lots of strains have purple stems naturally and its nothing to worry about. the yellow leaves could be a nitrogen deficiency, or it could be a nute burn from the miracle gro. ive read some nasty stories about that stuff taking out an entire crop cause of how hot it is. also, i highly recommend a good digital ph tester. i just got one and have made adjustments to keep my soil runoff right at 6.5 and my plants are already looking better with no nutes. if you havent checked this out yet, its pretty damn helpful:
Plant Abuse Chart

good luck man! i hope it works out for ya.

 

[voodoopoerk]

Hey thanks for the reply, i've been looking at those charts for weeks and everytime I think i've decided it's a nitrogen deficiency, i'll read something else saying it could be a Mg defic or sulfur defic, and thus they need more nutes! then i'll read that i'm nute burning them. The miracle grow only makes up for the top like 3 inches of soil at this point anyhow, I'm not sure if that would make a huge difference or not to how much the hotness of the mg soil effects my plant.

 

[Fuzzy Duck]

Many nutrient defs in the early stages may resemble each ofter in the early stages of development !

So it takes a keen eye & a little knowledge also information provided to help solve the problem...


How ever purple stems.

1. Could be strain related ?

2. P - phosphorus & even Mg - magnesium may show these signs if deficient in nutrients.

Normally go's away once feeding regime has been amended

 

[albchuk]

Check for potassium deficiency and ph and possible correct of ph to bring potassium def back in to range of availabily and up potasium slightly. Just an old nub suggestion