My plants (10 Easy Ryders) are in their 35th day or so and for a while, the leaf tips(ends of all serrated edges) have started to curl upwards. Im thinking its because of heat possible. The PH is steadily at 6.5, but the temp is usually around 81 degrees.

My setup is 10 easy ryders under a 600W HPS, which is in a closet with door open 24/7 and a fan blowing on them 24/7 as well. My growing medium is FFOF and i just started using Tiger Bloom and Big Bloom (Tips were curling before adding nutes). They are on a 18/6 light cycle. Any help would be greatly appreciated!! Here are some pics, although they are pretty blurry.....

07162009187.jpg

07162009188.jpg

My 600W HPS is about 14" away from tops of plants

put your light 18" away and see if that helps. i believe that is the recommended distance especially with rising temps.

__________________

"Remember, you can never overdose - you can only under-dose. We are just making sure we aren't under-dosing."

I am a medical marijuana patient - my plants and use are covered under State Law. I do not endorse illegal activities in or out of the state/country. So don't tread on me.

Spring '09 Grow Chocolate Thai: http://www.greenpassion.org/f24/back-action-spring-09-grow-7928/

Current Fall '09 'Red Diesel' LED Grow http://www.greenpassion.org/f24/fall-09-pure-led-grow-show-red-diesel-14415/

Upward curl is just that, heat stress, move that 600 up to 18" it's to close
Good vibes to ya

__________________

Fear is the only darkness that exist

Thanks-I will try to move it up to 18"

I get heat stress on some of my outside plants. I moved them to an area that is shaded from the afternoon sun. It seems to work.

That lamp is too close my friend. I had 2 400 watt lamps on my Canopy at 18" and experienced some light burns so I know with a 600 at 14" yer gonna be getting warm as well. Might try backing it up to around at least 18 or even 20". Remember that the heat generated from the lamp isn't the only concern. Contrary to what you may have heard you CAN have too much light. Light Rays can burn the hell out of plant tissue even if it feels very cool. Lenses do help but the light intensity can be overdone.Just think of it kinda like this, it's like burning our eyes looking at the sun(which I dont reccommend) only with the Plants it's burning their "skin"(Tissue)
Good luck,
Med

__________________

Your grow room might be 81 degrees.

But, 14" from a 600 watt HPS is probably well over 100 degrees.

__________________
-Michael

You may look into getting a sealed reflector, and properly venting it out. If you have enough ventilation you can let the tops of your colas get to within a few inches of a 600 without burn (not that I recommend it). A 6" turbine fan, like a vortex VTX600 or other comparable fan hooked up to a sealed reflector will make that 600 nice and cool.

In the mean time, are you running a form of silica? Silica can be very beneficial for reducing heat stress.

[QUOTE=6951A;128808]You may look into getting a sealed reflector, and properly venting it out. If you have enough ventilation you can let the tops of your colas get to within a few inches of a 600 without burn (not that I recommend it). A 6" turbine fan, like a vortex VTX600 or other comparable fan hooked up to a sealed reflector will make that 600 nice and cool.

In the mean time, are you running a form of silica? Silica can be very beneficial for reducing heat stress.[/QUOTE]

i find this very interesting....can you elaborate on this? How is the silica used and where is it? Thank you.

__________________
Life,
j-angel

aka GP purrie kittie attack cat!


My Little Grow LST'ing w/Hardware

My Outdoor Odyssey 2008 BONSAI MUMS

My Little Grow Indoor To Outdoor 2009

One brand would be silica blast, by Botanicare. My understanding is that Silica works by entering the plant cell tissue and essentially reinforcing it, allowing for more stressful environments without seeing stress.

I start using it once my plants have been transplanted into 3.5" pots and have overcome transplant shock. I continue to use silica until the carb flush in flower. Again, my understanding is that to fully benefit from the silica, you want it in as many cells as possible, meaning you want to use it throughout all stages of growth as I believe it enters the cell when it first forms.

i saw your thread and it caught my eye. i remember from a long time ago, that silica can be a component of plant leaves especially in monocots like rice and turf. so i checked out that product you mentioned, and did a quick little research on silica and leaves.
first off, its a naturally formed silica by the plant. it occurs in the epidermal tissues of the leave, and can give the leaves a glossy appearance. this silica is formed by the plant and not absorbed by the plant. the purpose of silica in leaves has not been identified, but is suspected as some type of uv protection for the plant.
the benefits of your product "silica blast" is most likely from the potassium silicate that it is made up from. plants can consume more potassium than they need with out doing them any harm. higher potassium levels would give the same side effects as you listed for the product. if you feed well already, probably something that is not needed.