Stumped!! Any ideas?

Hi all

I've had a good look at the different pics of deficiencies, and I still can't be sure what my plants' problem is!

Is it blindingly obvious to anyone else?

Used to happen in week 7 (of 9), but is now occurring as early as week 3.

Impossible to even make a guess without grow-data but it looks like a Micro-deficiency to me. Give as much info. as you can.

Hi Carl

Sorry - it's my 1st post to the forum - wasn't sure how to go about it. How's this:
Strain: Jack Herer
Grow type: Hydro grow at 3½ weeks flowering
Indoors
Readings: pH 5.6, Ec 1.6
Room temp: between 25C & 30C at the moment - hot days!

Please let me know if there's any more info you need.

Thats heat stress and light burn..... back up the light... are you running Ozone?

That does sound pretty hot but I'm not sure I would try to modify anything you are doing right now that would contribute more stress-factors. As the temps. moderate things should stabilize and resume normal growth, if not I would look at micro's that are used in larger proportion such as Fe, Mg and Ca as your current numbers look good.

Thanks Scotty. I'm beginning to think that whatever the deficiency is, it's been brought on by high temperatures. btw what's Ozone?

Thanks Carl. Yep - will try to restore heat order in the room!

Sorry that I'm such a newbie to posting here. i've finally read the checklist for plant problems, and here are my full answers in case they help further diagnosis:

What type of medium; soil or hydro? Hydro
Indoors or outdoors? Indoors
What strain? Jack Herer
How old are the plants? 7 weeks
What type of lights and how many watts? HPS 600 watts
How far from the lights? 12 inches
What is your watering frequency and source of water? Tap water, frequency same as lights
What, how much and when was it fed? Scotts Peters
What is the medium/runoff pH and PPM if in hydro? 5.9pH & 2.0Ec
What are the temps and humidity in the room? 29-30 C
What size pots? NFT
Any bugs? No





2) Growing indoor or outdoors indoors
3) Watering schedule as lights
4) Growing Medium rockwool
5) What stage of growth 7 weeks into flower.


Your Equipment:
.1) Type and wattage of lights. HPS 600w
.2) Distance from tops? 12 inches
.3) Reflector type? Basic reflector
.4) Is there a consistent fresh air supply? Yes
.5) Do you have an exhaust fan and a circulation fan? Yes
.6) What are the bulb wattages, kelvin ratings, and schedule? 12/12 HPS, 600w, no idea about kelvin
Your medium:
.7) Specific brand and type of soil. Rockwool cubes sitting in hydro
. Size of container. 20L
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings? no

Your nutrients and water:
10) Source of water? (tap, bottled or filtered) TAP What's it's ph before adjusting?--- 7.4
11) Method of checking water ph. ph meter
12) Method of adjusting water ph. PH down.
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule.— Scotts Peters
[FONT=&quot]14) How often are you watering between feedings, and how much per watering?
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...) no
16) Are your ph levels stable, or do they fluctuate? 6.0-5.5
17) What is your ingoing water's ph? ...your runoff ph? 6.0
1 Do you foliar feed? If so, with what, how often, and at what time do you spray? no

Your growroom:
19) Indoors or outdoors? indoor
20) What size of closet, room or hut? Room 12x12
21) What are the temps and humidity levels while lights are on? 30C & 25% ...With lights off? 20C & 40%
22) Have you seen signs of insects in the growroom? no

Your strain:
23) What strain are you growing? (Indica dominate or Sativa dom?) Sativa.
24) From seeds or clones? clones
25) Is this an autoflower strain? no[/FONT]

thanks again guys

Those green veins are indicative of a magnesium deficiency. Looks like they could be lacking some calcium too, so I'd say to step up the Calmag. It'd also be a good idea to flush, then give them a good feeding afterwards, giving them a fresh start. It'll also bring the PH up some.

I still say Heat stress a 600w HPS is a serious bulb and should be 18" away from the tops.. I use to run a 600w HPS with a PL reflector and had to be 24" away from the tops or it would cause bleaching and heat stress just like yours ...

Ozone also causes similar problems, it comes from ozone generators it kills smell like you would not beleave however its a balance cause it can also start to kill cells in the leaves.. (ive had that problem in the past too)

I would also look into GH Nova Nutes to cancel out any problems with nutes for your future grows..

thanks Jaw & Scotty. good advice, well taken!

^I also agree that it looks like possible ozone damage, especially the pic of the single leaf. I had that happening for a couple months(hot months), back when I didn't have a good ventilation system. Got the air movin, and the temps down, and that was the end of it. I'd look into those, too, if you think your growroom is susceptible to ozone damage(along with the deficiencies).