In need of help (pics included)

All of the plants are northern lights. Seeds from nirvana . They are in Dr. Earth pot of gold soil with about 30% added perlite. They are about 6 weeks old from seed . I've been watering every few days only when the pot felt light and the soil was dry . The middle leaves on some of the plants started getting this orange/brownish spots . Kind of looks like rust spots on the leaves . Those leaves all have dried up so I cut them off .
I've been feeding them superthrive and jobes tomato fertilizer at 1/2 strength .
They're in a closet that is about 2ft wide , 3 1/2ft long and about 8ft tall .
Grown under 10 23w 6500k cfls
And 4 13w 2300k cfls.
My temperatures are right around 85f.
Is it to hot in there ? I have fans blowing on the plants to keep them dancing .

Do you know the ph of your soil?
Growing in a closet I'm guessing your fan must be close to your plants, try not to aim it directly on your plants at this distance, It may cause stress.

You want to keep a ph between 6.2 - 6.7, if it is outside this range, your plants will not be able to absorb nutrients and deficiencies occur.

That looks like light burn mix with iron deff. And meg deff for sure

maybe needs some calcium

I don't have anything to test the pH.
I was able to get the temps down to around 78 to 80 and I don't see any further progression of the spots or damage. Could it have been heat stress and light burn?

Too hot. Keep it at 80 and under and it'll sort itself out in a week or two.

tomato fertilizer has simlar NPK values for flowering nutes, are your plants in flower, for some reason i cant see your pics ?

Not trolling, but just sayin, u should never start a grow without a ph and tds meter. it would be like a mechanic opening a shop without a set of wrenches.

apbx720 said:

Not trolling, but just sayin, u should never start a grow without a ph and tds meter. it would be like a mechanic opening a shop without a set of wrenches.

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Not bad advice, but the analogy is a bit hyperbolic. I would bet better than half the growers here do not PH. That said, I did have to do some dialing in my first few grows 6 years ago. I did so without checking PH. Once dialed in with the same water supply and the same medium...grow after grow. I find no need to PH.
So I would change your analogy to a mechanic who is missing 1 wrench.

most of that half don't ph anymore because they've learned their set ups and know what their water/nutes do together.
the rest of them don't do it because they're stupid, lazy, or both.
till you learn what you're doing, get a ph and a ppm pen, and use them.
looks like cal and mag deficiency, possibly ph swing damage, and burn from heat and too much airflow. stay under 85. under 80 is better, over 85 and damage starts to happen. don't have air blowing directly on your plants unless you have very high RH, even then its better to aim fans at the walls and let the backwash hit the plants

Roger A. Shrubber said:

most of that half don't ph anymore because they've learned their set ups and know what their water/nutes do together.
the rest of them don't do it because they're stupid, lazy, or both.
....

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First, you just repeated what I said my experience was. I learned my setup...while in that time I was still close to pulling a lb. off a 600w in 3.5 months. (Yes, I do more than a lb now)
Second,i it doesn't take a PH meter to recognize a PH problem. It takes some intellect That was the wrench I used. You should try it.
Lastly, <insert substandard colloquialism here>

ok, your dick is huge, and you don't need a ph meter. the rest of us average people use them, because we don't have your super intellect.

Roger A. Shrubber said:

ok, your dick is huge, and you don't need a ph meter. the rest of us average people use them, because we don't have your super intellect.

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Didn't say anything about my dick nor did I brag about having a super intellect...although you might be psychic. I now imagine both your dick and your brain being the size of a peanut. Remember friend, you started the insults while you should also re-read my first post as I am pretty sure it started by saying a getting a PH meter is good advice.

That said, Although your dick might be the size of a peanut, it certainly is an arrogant prick.

jobes tomato fertilizer has an NPK value of 6-18-6, your problem or at least one of them is phosphorus toxicity

No , the plants are about 7 weeks in veg.
I'm only going to flower them when and if they bounce back to normal. The leaves closest to the lights are fine , it's the middle leaves that are showing the problems.

Illicitmango said:

No , the plants are about 7 weeks in veg.
.

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SO WHY ARE YOU GIVING THEM FLOWERING NUTES NPK 6-18-6 ?

you need to be giving them something closer to 5-1-2 during veg, then something like 1-4-3 for flower

Tomato fertilizer I used was 2-7-4. and I only fed that to them one time, about 3 weeks ago at half strength.
Since then I've been giving them superlative,
And that I've only been given at 1 drop per 4 ounces of water.

Looks like Ca deficiency (mid leaves) but not Mg (lower leaves). I also think you need to give them some N but it is hard to tell as the color fluctuates between your pics. I have been really happy using Jack's Classic 20-20-20 in veg and it is a bargain.

Here's some more pics . Any advice is greatly appreciated.