Name the problem

The First and Third pictures are the same fan leaf, the Second picture is a healthy leaf on the same plant. What do you guys think? The problem is only effecting the fan leaves, maybe the light was to close? The light was about a foot away from the plant, the plants being around 10 to 11 inches tall this started a few days ago since then the light has been raised 3 feet above the plants. The problem has already turned a few fan leaves crispy and they were cut off. The plants are in 5gal pots with Supersoil they are almost a month old and are watered around twice a week, once this week since the soil is still damp a inch deep. They are watered with a gallon of water mixed with a little over 1/2 a cap of FoxFarm Grow Big and a cap (about 1/4 teaspoon) of Superthrive, drainage is good this is only affecting 1 strain (caramel a indica/sativa hybrid) which is 2 plants of four plants the other two plants are Grand Daddy and Purple Haze (which is doing verrrryy good). And they are under a 600 watt hps hortilux bulb 24hours a day, ventilation is great, temperature is staying around 70 although a few days ago it did drop down to 52 which was around the time i started noticing the problem. The plants were in shock for a day but they came right back kickin' and the problem has been consistent with a few more fan leaves since then while the temperature has been stuck at 70-74. Ssooooo... What do you guys think?

the PH is good and I foliar feed with straight water every now and then.
O ya no signs of pests.

Looks like over fert to me but I am no expert. I had similar symptoms when I use to use shitty soil. But thats all changed now!

thats what I was afraid of, any other suggestions?

Sol02 said:

the PH is good and I foliar feed with straight water every now and then.
O ya no signs of pests.

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When you say you foliar feed with straight water, do mean water that has been sitting out for for atleast 24hrs and has bin ph'd.
What's your ph?
Do you have a moisture meter?
Are you using nutes everytime you water?

Ph is so important. Add your fertilizer to your water and then test your ph level. Like major said let that water sit at least 24 hours so the chemicals in it can evaporate. Also use measuring spoons instead the cap to measure out your fertilizer. That way you will know exactly what amounts you are using in case you need to change.

yes Ph is neutral at 7, humidity sticks around 40-50, nutes have been used the last 3 feeds

The pH of distilled water is 7.0, this is neutral. Any solution with a pH below 7.0 (i.e. pH 1.0 to pH 6.9) is an acid and any solution with a pH above 7 (i.e. pH 7.1 to pH 14) is an alkali. The pH scale is logrithmic, that is, a pH 6.0 solution is 10 times more acidic than a pH 7.0 solution (pH 5.0 is 100x more than 7.0!).

Acidic solutions have a pH between 1 and 6.9 (your stomach contains HCl it is pH2).

Alkaline solutions have a pH between 7.1 and 14. (your small intestine is pH 9).

Neutral solutions are neither acidic nor alkaline so their pH is 7.

Weird facts.

Two things, cold damage to the leaves, and too much nutes. I don't know about the amount of Fox Farm, but I know that you don't need to feed so often. And the Superthrive I use also, but at 1 DROP per gallon.

HTH

So its looking like over fertilized then, so the best remedy would be to flush it with water at a neutral 7.0ph with no fertilizer. Water now (its been 6 days) or when the soil is dry?

what does it mean when the leaves start curling up from the sides?

Sol02 said:

The First and Third pictures are the same fan leaf, the Second picture is a healthy leaf on the same plant. What do you guys think?

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It's hard to say without more information ie where the leaves are - are they at the top or bottom of the plant etc but from what you've described and looking at the pictures I'd say it's either nutrient burn (too much nutrient in the feed solution) or heat burn - lights too close (a 600w HPS or MH should NOT be 1 foot above the plants) particularly if any water happen to get on the leaves. Even if you haven't been foliar feeding and left water on the leaves, leaves can transpire water onto a lower leaf and that acts as a magnifying glass for the light and heat coming from a light source already too close and burn the tender leaf.

You've already solved one potential problem by moving the light further away, get a more accurate way of delivering nutrient solution to your feed water (use a pipette or syringe) and ease back off the nutrient solution by half and monitor it.