WW clone issues on leaves

[JohnnyToke]

Here is a WW clone in recirc DWC. 4 plants total in system. only 1 plant showing these symptoms. these leaves started showing this yesterday morning. Any ideas as to what is the cause?

How long has this problem been going on? - noticed 36 hours ago
What system are you running? - DWC, chilled & Recirculating
What STRAIN are you growing? - WW
What was the establishing technique? - Clone from mom
What is the age of your plants? - 16 days into veg from rooted clone
How tall are the plants? - 9" when not lst'd
What PHASE are the plants in? - veg
What Technique are you using? dwc w/ lst then scrog
What substrate/medium are you using? - hydroton
What is the Water temperature? - 67f
What color are your roots? white
Are your roots slimy? - no
What Nutrient's are you using? gh novagrow
How much of each if using multiple? - 60ml for 20 gal
What is the TDS/EC/PPM you are using? - 790 ppms
What is the pH of the "Tank"? was 6.3 yest, lowered to 5.9. current 5.9
Are you sure your calibration is correct on your equiptment? - yes, I have 2 different ph meters, both read the same.
When was your last watering? - n/a - dwc
When was your last feeding change? - 6 days ago
How often do you clean your system: the buckets & rez are brand new for this round
What size bulb are you using? - 2 x 400w cmh
What is the distance to the canopy? - 24"
What is your RH Factor(Relative Humidity)? - 38%
What is the canopy temperature? - 74f
What is the Day/Night Temp? on 24/7 so low 70's all the time during veg
What is the current Air Flow? 24/7 with 6" vortex (449cfm)
Is the fan blowing directly at plants? - there is a oscillating fan in there
Is your water HARD or SOFT? - Hard
What water are you using? - RO - 10ppms
Has plant been recently pruned, cloned off of or pinched - just lst 2 days ago
Have any pest chemicals been used? - no
Are plant's infected with pest's - no

I appreciate any input.

regards,
JT

 

[mdanzig]

Bring your temps to 78-80 degrees all the time, and reduce humidity. Looks biological.

 

[PharmaCan]

Your pH is way too high and you're locking out Nitrogen, probably along with most everything else - but that has nothing to do with the leaf damage. If you are using r/o water you need to replenish the good stuff the r/o takes out of the water. CalMag+ would probably be your best bet to take care of that deficiency.

But get your pH down to a proper hydro range first and foremost.

PC

 

[JohnnyToke]

thanks for the replies. I adjust PH once a day.

the 6.3 PH I listed on there was the PH before my daily adjustment back to 5.8 / 5.9.

the rest of that plant and other plants seem to be doing fine. this is my first go round with white widow so there may be an adjustment period getting everything dialed in verses other strains I have grown in the past.

I have cal-mag on hand but have not used any yet for this grow. My last grow was Northern Lights and it didnt require any cal-mag. this WW may be different.

ill keep a close eye on them. growth seems to be good and they are putting on new foliage. the one plant with the 2 damaged leaves is the biggest of the 4. go figure.

regards,
JT