Leaves turning light green

[jakej941]

My leaves are turning a light green color. This is mostly happening to the topmost leaves but on a couple plants it goes down further. It is only happening to a few of my plants and they are all in the same room with no difference in light, nutes, water.
They are in pro mix,perlite, sand mix and are about 12-14 inches from my 600w mh with air cooled hoods. They are about 5 weeks old. I have ruled out overwatering(I let them dry right out) and too close to the lights. Temps are good, 75-80 day and 70-75 night. Hope this is enough info. Thanks
They look quite a bit lighter than pics show. Also one pic is of healthy plants. Couldn't post pics

 

[WizHigh]

Are you not on a computer the reason why you couldnt post pics? You will need pics for good info or a more accurate answer but it could be a wide of things happening to your plants. How does the new growth look?

I would say how much are you feeding to your plants and what?

What stage are the plants in, veg-flower? how many weeks?

 

[Muttt]

Mine where doing that. It turned out to be 1) needed more light 2) needed more nutes 3) needed more water. Once I solved those issues, the problem went away on it's own. It appears that light isn't part of your problem. But, I would move it farther away .... at least 18-20 inches. With a 600w light you got plenty of light. You don't need to be as close.

 

[GigaGrew]

its common for unstable phenos to diplay different behaviours. if your plants tend to look different then they probably are. i have some plants that are dark green, some that show minor deficiency/lockout and some that are a pleasant pale green. water/light/food/soil is identical and they are all called the same 'strain'.

temps look good, certainly enough light. make sure to prevent salt build ups with flushes, avoid dry spots in the soil as this can be the cause of your symptoms.

personally i would have skipped the sand as it doesnt bring much to the table to be honest...its neither a food source dor as good at airation s perlite.

you say 5 weeks old, but you dont mention your light regime or if thats 5 weeks of veg or your flowering e.t.c

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