Heat stress/nute burn?

So a little background, this is my first grow.

I'm growing in a 72sq ft 'walk in' closet using a dwc setup with rock wool as a medium. I know I'm gonna get slammed for this right off the bat, but I don't know my ph. I just use fresh drinking water.

I'm using 7.5 ml of sensi grow a&b nutrients per 2 gal of water.

6 cfl lights. 5 are the 23w 5000k? (Bluish color) and 1 26w 2700k? (Reddish color). I mixed them up because I read that it imitates sunlight better. Don't know if it helps anything but what the hell.

The strain is afghan kush, but it's beginning to happen to my deadhead og also.

It's been mid/high 80s lately, so it gets 90 or so inside. I keep the closet door open and fans on constantly with a box fan at canopy level.

Basically I understand it could be any number of things. I read the moisture stress thread and found myself able to relate with half the symptoms that were listed. I'm just looking for a little wisdom

You gotta help yourself here and test your ph. Not slamming you, just stating the obvious for any hydro grow.

Bugeye said:

You gotta help yourself here and test your ph. Not slamming you, just stating the obvious for any hydro grow.

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No worries, it was expected lol. Thanks for checking it out

Your temp inside the closet is 90+? Just want to make sure that I understand. With it being a dative dominant, I would think the heat is not that big of an issue. I have sativas with 90+ temps, but good air flow, and the worst I get is the occasional leaf burn from my cfls. Do you know your humidity?

As far as your ph goes, I am more knowledgable in the soil side of things although through my research on DWC, ph is important. On the other hand. I know what it's like to slack on spendin money on things and actually going to the store to pick something up that you need for a pot plant alone. Although walmart now carries a simple ph kit for around 12 or 10. It comes with the disposable strips that should at least last you threw this grow for you.

Its looks to me like ph problems. My tap water is 8.5 by default your gonna want to get a ph up and ph down kit with a ph tester. Mine was like 15 at the local hydro store, and it really helped me fix my problems. My leaves looked almost exactly like yours before I figured this out.

Oh and where does your water come from? Tap, hose? I am lucky and have the luck if watering feel. Purified water, but, it IS for soil.

4Life2style0 said:

Your temp inside the closet is 90+? Just want to make sure that I understand. With it being a dative dominant, I would think the heat is not that big of an issue. I have sativas with 90+ temps, but good air flow, and the worst I get is the occasional leaf burn from my cfls. Do you know your humidity?

As far as your ph goes, I am more knowledgable in the soil side of things although through my research on DWC, ph is important. On the other hand. I know what it's like to slack on spendin money on things and actually going to the store to pick something up that you need for a pot plant alone. Although walmart now carries a simple ph kit for around 12 or 10. It comes with the disposable strips that should at least last you threw this grow for you.

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I have a little thermometer on one of my fans, don't know how accurate it is but the high of the week has been 90 in the bedroom. I imagine the closet to be a few degrees warmer. But the closet is about 3 feet from a window with a fan blowing air into the bedroom, and a box fan blowing air into the closet. And as far as spending money/getting to the store, you're exactly right haha. And the water is those big 5 gal bottles. I forget what brand it actually is but somewhat like arrowhead

Chris Benson said:

Its looks to me like ph problems. My tap water is 8.5 by default your gonna want to get a ph up and ph down kit with a ph tester. Mine was like 15 at the local hydro store, and it really helped me fix my problems. My leaves looked almost exactly like yours before I figured this out.

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Awesome, thanks for the heads up. I'll definitely pick up a test kit asap. Hopefully it's something so simple haha

Bignasty1326 said:

I have a little thermometer on one of my fans, don't know how accurate it is but the high of the week has been 90 in the bedroom. I imagine the closet to be a few degrees warmer. But the closet is about 3 feet from a window with a fan blowing air into the bedroom, and a box fan blowing air into the closet. And as far as spending money/getting to the store, you're exactly right haha. And the water is those big 5 gal bottles. I forget what brand it actually is but somewhat like arrowhead


Awesome, thanks for the heads up. I'll definitely pick up a test kit asap. Hopefully it's something so simple haha

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The kit is very simply. And you may not need a hydro shop to get it. Although I have a HTG supple. A bit pricey but they got anything I need, with the option to see it first and freebies!!

4Life2style0 said:

The kit is very simply. And you may not need a hydro shop to get it. Although I have a HTG supple. A bit pricey but they got anything I need, with the option to see it first and freebies!!

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Haha lucky. But yeah I figure Home Depot or something will have one. If not I know of a few hydro shops in my area. No freebies though