edges of all leaves curl upward...

[The Dank]

One of my plants is being weird. As a seedling, it did have too high of a ph, but that was corrected a long time ago after I noticed the first set of leaves were yellowing. Ever since for the past 2-3 weeks, it has looked great, but the edges of the leaves curl upwards. The ph has stayed steady at 5.6-5.8. Using the lucas formula, GH nutes.

Any ideas?

What STRAIN are you growing? Rosetta Stone (old stock)
What was the establishing technique? seed
What is the age of your plants? 3ish weeks
What PHASE are the plants in? seedling, vegetative
What Technique are you using? DWC hydro
What substrate/medium are you using?(Hydroton)
What is the Nutrient temperature? 68-69 F
What Nutrient's are you using? GH Lucas
What is the TDS/EC/PPM you are using? 440ppm
What is the pH of the "Tank"? 5.8 and steady
Are you sure your calibration is correct on your equiptment? No, using a nice Milwaukee Meter, but it's 3 years old.
When was your last watering? n/a
When was your last feeding change? 2 weeks
What size bulb are you using? 430w son argo hps
What is the distance to the canopy? 20"
What is your RH Factor? 50%
What is the canopy temperature? 70-80 F
What is the Day/Night Temp? (Include flucutaion range) 55-65F night 70-78 day.
What is the current Air Flow? (vortex 6")
Is the fan blowing directly at plants? no.
Is your water HARD or SOFT? 7.0ish PH 130ppm
Has plant been recently pruned, cloned off of or pinched no
Have any pest chemicals been used? If so, What and When? no
Are plant's infected with pest's no

 

[MynameStitch]

Looks like you may have your lights a little too close for the plants liking... the leaves are curling upwards which means dry heat.... those 400's love to give off the dry heat thing.... raise your light up a bit... the plant is very small to have a 400 like that as close as it is....

You have that light 20 in away?
Your ppms are fine, not too high.
You calibrate your meter every 2 weeks? You should always re calibrate it every 2 weeks max.

 

[The Dank]

I calibrate it about once a week...thanks for the help, i'll back the light off a little!

 

[The Dank]

Oh yeah, what would say is a safe distance at this point?

Thanks again!

 

[MynameStitch]

Do you have a temrmoeter to test the canopy temps? A digital one? You want to keep canopy temps under 80..... 75 is the best temps.

When you use an hps on small plants like that you will get some stretching, because in order to keep it at a safe distance to stop this problem they have to stretch up to the light a big, 400's don't offer good penetration at higher distances.
Using compact fluros or MH on plants this size, speeds up growth and will be the proper spectrum where HPS is used for flowering, does not mean you can't use them for veg, but it will cause slower growth from higher wattage lights and improper spectrum and a combination of not being able to keep the light as close to the plant.

Each strain is also different which you can keep lights as close to it.
Some have more heat resistant than others too.

 

[The Dank]

okay wow, I just realized that I had the light 9" away from the canopy, canopy temps were at 78F. So I raised it to 17", canopy temps will prob. drop a few degrees, but I think the main problem was it was like 9" away!

 

[MynameStitch]

Yup, see

Problem solved! those leaves will problem crisp up soon and brown since the leaves were damaged due to the dryness; so I would not worry about them if they brown up, now if new leaves soon brown when they were not there, that is different

For now, this is very simple which you fixed it; so you should not have any issues now

 

[Oizo]

I just made a simular mistake.. except i was using 1k for little babies 1ft away. ahahhaa im not used to all this fkin power... mistake corrected!

 

[MynameStitch]

I made a slight mistake myself, when I first bought me a 1,000 hps sun system; and I was testing it and I left it a little too close for a day and the next day it had light bleached the entire leaf from the lumens; the hood was air cooled by a 6 in vortex.

The leaf had been stripped of it's green entierly; looked like it was a ghost plant lol