How high are your lights?

Whats happening i have a 600watt MH bulb, it was recently about 8in from 2week old plants. they were getting fried i guess, brown spots appeared. I jus brung em' up to about 18in , Whats the average light hieght?

this looks like an ok height, maybe a foot wouldn't be too close. feel close to the light for a min or 2 and see how close you can feel the heat coming off of it

If you have some money, you can try switching to a cool tube for your light. You should get a fan too if you use to cool tube.

Also maybe position a fan facing up towards the light to draft the hot air away from the plants.

thanxs for ya time, i just placed a clip on fan diercting towards the bulb, DO you farmers think the spots came from the light being so close to the plants?

It's possible if the spots are only on the tops of the leaves... if you even have enough sets of leaves to be able to notice a difference. From the looks of it, I think your light is far enough away... however 600 watts is mighty powerful if its not properly air-cooled. It's good to get reflectors/hoods for your light that you can seal off, and cool the light by pulling in fresh air and exhausting into a different room/area. That should eliminate any possible heat stress.

Your PH may be off as well. It could be a lot of things. In fact, after looking at the pics again I don't think it is heat related since the new growth is very green, and the lower leaves are what's suffering. You should re-evaluate what you're feeding the plants. Could be a combination of feeding problems and the light not being cooled... my personal opinion at least

yesterday i drained everything, listen to this one, i never cleaned the hydroton so i cleaned it untill clear water was flowing. The roots were dirty color. I Balanced the PHto 5.5-6. The nutes i give em 2.5ml of each floragrow, micro, bloom, and fum flora blend. Are the plants in danger? HELP!!!

I'm not experienced with the General Hydroponics brand, but it sounds like you're following their feeding schedule. You might want to increase the floragrow so the plant gets a bit more nitrogen. And you might want to have your PH closer to 7, something more neutral. Eventually you'll have to cut those lower leafs off that have the spots anyways so dont freak out, and hopefully all of your new growth will stay positive.

Thanks man a lot of help i shall do that, whats r u running ganjales?

Looks like nutrient burn. I've seen plants burned from a light and it didn't look like that. Really early to be giving nutes too. I don't introduce nutes until week 3 for seedlings and at 1/4 the recommended strength.

my no-brainer method to check the proper light height:
I hang my thermometer with a string from the same place the lights are hung.
I place the thermometer at the level of the top of my plants.
I check if the temperature is ok, and if it isn't I adjust.

Right now its really hot outside and somehow I'm keeping 31 at lights on and 29 at lights off. my light come on at night. I use a cooltube with a 560m2h fan and currently the lights are about 40cm from the tops.

Thanxs 2 err1 again...sounds like a nyce setup bro, I had them under a 100watt flourescent for 2 weeks then i moved them under the 600w MH bulb. there set up to about 16 inch from plants.

cr8z13 said:

looks like nutrient burn. I've seen plants burned from a light and it didn't look like that. Really early to be giving nutes too. I don't introduce nutes until week 3 for seedlings and at 1/4 the recommended strength.

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oh no its debo! Hide your chains!

DEBO who i wear mines!! lol