discolouration of leaves, can someone pls advise what prob is?

[Boohiss]

Howdy all,

 

This is my first grow so lots to learn but so far I haven't been able to pin down what's wrong with one of the plants I'm growing.  Basically the leaves are a mottled colour with patches of yellow in them.  The leaves also don't look smooth.  I'm growing 2 other strains that are not showing any problems.

 

I have been feeding this seeding for 2 weeks using Canna Classic A & B using the amounts as specified on their website, I'm feeding them once a week only.

 

The only issue I had was leaf burn when it was a very young seedling due to low humidity, this is no longer occurring however the humidity in the Grow Tent is still below 30%

 

I've attached 2 photos of the same plant to help diagnose the problem, many thanks

 

 

Indoor/Outdoor:   Indoor
Growing Medium:   Coco
Growing Style:
Watering/Feeding Frequency:   every 3 / 4 days, using finger to confirm the coco is dryish
Nutrient Strength (PPM/EC):   Don''t know
PH Levels:   6.5
Temperature/Humidity Levels:   28 - 30 degrees.  Humidity is below 30% (meter does not register humidity below this point)
Air Flow/Fans etc.:   Centrifugal extraction fan, 2 passive intakes
Lighting Type (CFL/HPS/MH etc.):   HPS
Total Wattage:   250
Growth Stage:   Growth
Plants Age:   3 weeks
Cannabis Strain:   CBD Crew, Yummy

[Chato]

Have a read of some coco diaries first and foremost. Secondly drop your ph. Lastly use a coco specific nute.

 

peace

c

[forgetiwashere]

Did you flush afyer you burnt her. My guess is you overloaded her with salts and now shes locking them out. I would suggest a good flush with ph'd water an a feed of halfstrength nutes to ease her back into life. After that just try and keep everything in check and she will pull through

[GreenGoat]

drop your ph by a unit when feeding. PH @ 5.5 - 5.6 when feeding seems to have fixed this exact problem with me. If you are feeding at 6.5 is this as per your bottles lable? in which case i suspect your nutes are for more traditional hydro not for coco growing. This could cause deficiencies (your lowest leaves are more pale and yellow then the top ) and the warping is likely from PH being too high
Thanks goes to Doc-Who and hash-Nibbler for the advice I'm regurgitating. I'd highly recommend having a read of hash nibblers tutorials listed in his signature!

 

Issues with Coco can be in abundance, especially with the cheaper coco. Use coco specific nutes, a lower PH when feeding, flush them every now and then to remove buildups of salt and other unwanted/needed minerals but otherwise coco should be ok for us noobies

[forgetiwashere]

whoa yeah i somehow missed that you are running a 6.5 PH it should be between 5.5 and 5.8 for coco.

[buzzo]

Actually between 5.2 & 6.2 with 5.8 the target, this is for Coco not other mediums.

It will tell you that on the Canna Coco Label.

 

Digital P.H Meters are cheap on ebay.

Edited July 8, 2013 by buzzo

[bufo marinus]

I'm geussing you've used the cheap shit compressed coco from Bunnings, even at 6.5 the leaves should not look that colour.

[Bentato]

if it is the cheap bunnings stuff its potentially loaded full of sodium chloride.

 

Id flush the living hell out of it with plain phed water (to 5.8), followed by half strength coco specific nutrients phed again to 5.8.

 

When repotting if you are using the cheap coco i wouldnt use the same stuff again, instead id get some quality coco from the likes of canna, h&g or way2gro