Please help - Yellow splotchy growth on young plants

[greenPlantern]

Let me first start off by saying that I'm new to this site, so I'm not really sure where to post this thread, so I apologize if I'm in the wrong section, this is my first real grow and I've noticed strange yellow splotches on 3 of my plants and I'm hoping someone can shed some light on this problem. They where started from seeds (GHS white widow) I have them under a 1000w hortilux super blue dual arc bulb, the hood is air cooled with with a 6" 470 cfm inline exhaust fan, temperature is 78 degrees lights on, and 67 degrees lights off, they are on a 20/4 light cycle, the grow medium is my own organic soil mix of perilite, vermiculite, bloodmeal, bonemeal, water has been tested at a ph of 6.5, and is room temperature. Please help I don't want to lose these little babies, and I feel like I have all my basis covered.

 

[greenPlantern]

 

[greenPlantern]

Here is a pic I appreciate all input

 

[CO Finest]

Hope you do not mind me asking for more info.
Is that you run off pH.
If that is not your run off you might need to bring pH around 6.8 you soil might be buffering pH to low

 

[greenPlantern]

Just tested my runoff and I'm using the drop test, I'm guessing since the water was already a light amber color, I should account for that, so I'm thinking it's probably 5.8 (+)(-) .3

 

[shottafire]

How high up is your light?

Have you fed the plants with anything other than plain water?

 

[greenPlantern]

No I've only used plain water up till this point, and my light is 24" above the plants the canopy temp is a constant 78 degrees. Now I've noticed a few maybe 4 or 5 fungus gnats, do you think this could be the problem?

 

[shottafire]

No the fungus gnats are not likely to be the cause. I think you need to back off on the lighting. Try the light at 36-48 inches and I think you should see an improvement.

To take care of the fungus gnats just get some yellow sticky cards and treat some of your plain water with gnatrol or mosquito dunks which they are one in the same I believe except gnatrol is liquid and the mosquito dunks need to be bubbled in your water for 12-24 hours

 

[Lady Cannafan]

I agree with where Shottafire is going about the light height. That almost looks like light burn from the light being too close. If you place your hand just above the plants for a while and it's gets uncomfortable hot..the light needs to be raised. The area of the yellowing and the slight curling of the edges of the leaves, looks to me like the leaves are trying to protect themselves from the heat.
That's my thoughts.

 

[greenPlantern]

Thanks alot! I'll try this and update soon

 

[greenPlantern]

You guys are life savers...New growth is green and splotch free. Now time for this fungus gnat genocide! Thanks!!!

 

[Grayhawk]

have to be in the water. I had few first time planting with burning. the water here is so hard and chemical. I ended up buying spring water to help mine. now I use the same tap water but leave water out few days before adding to plant. I heard that doing that will release chemical from it. or just go buy clean water. farely cheep.

 

[greenPlantern]

 

[greenPlantern]

These are the ladies yall helped me save... On behalf of all of us...Thank you