1st time grower please help

[hbenz]

strain - cheese indica dominant
#of plants - 21
type of grow - soil
grow stage - week 3 flowering
bucket size - 9 litre
lighting - 2x 600W hps
nutrients - budzilla 30-30-70, earthjuice catalyst, headmaster organic bud enhancer.
medium - terrazilla premium soilless mix
p.h - 6.5
ppm - ?
relative humidity - 45%-65%
room temp - 62f-80f
solution temp - ?
roomsize - 2mx2mx2m

problem - random leaves showing yellow spots around the top to mid area of plants, tips of other leaves around base of plant curling and drying up with a greyish colour also some younger growths drying up and curling aswell.

extra notes - lights are run 7 hours each with a 1 hour period in the middle when both lights are on giving them a 12/12 cycle.
- have done a tonne of reading and the symtons are similar to a phosporus def/heatstress/nuteburn/lightstress/underwatering? maybe.
- dehumidifier runs 24/7 could this be a problem?
- this is not hapening to all of my plants and is mainly present in the plants closest to fans/dehumidifier etc. although some plants further away show minor symptons


any input would be apreciated cheers guys

 

[Thawk]

I'm far from a guru so you may want to take my advice with a grain of salt but I can offer you what I know. First off I would try and stabilize your temp some, an 18 degree fluctuation is rough on a human, much less a plant. As far as your problem a couple questions, did the yellowing all start at the top? Is the bottom yellowing? A pattern to the crumbling leaves? Necrosis? Here is a guide that you can use to find problems:

Cannabis Plant and Pest Problem Solver - Pictorial

 

[hbenz]

hey thawk, stabilizing my temp is a good place to start cheers, as for the yellowing no it didnt start at the top but about 3/4 the way up. the bottom is a lil diferent its more curling of new growths and drying out turning a greyish colour of the bigger leaves. i appreciate the help mate keep it coming....benz

 

[Thawk]

Hmmm is there anyway you could get some pics up? Be careful to not over water, but I fel like it may be a couple different things but I wouldn't want to give you any advice till I saw a pic, a correcting something that's already ok could kill your plant...

 

[hbenz]

yea mate will put up some pics soon as lights come on jus got camera back cheers

 

[hbenz]

heres sum pics of the damage and my grow

 

[hbenz]

i have been watering with tap water with a ph of 7+ could this be the problem i bought sum ph down today, do you think flushing them with ph'd water would be a good idea? my temp is 69f-80f now. note- all photos are taken from the middle and lower regions of the plants.

 

[hbenz]

thawk where are you buddy????????

 

[Wingman420]

Hey there hbenz my friend all looks good. While you do have some issues I would not be overly concerned at this stage. I do not think the temps are the problem as I have grown outside in New England where temps change 30 degrees daily. You do not need to run a dehumidifier unless you live in an area where humidity is high. I would turn off the dehumidifier, I hardly ever use one, only in the summer during a heat wave. Remeber these plants grow outside in places like Afghanistan and can thrive almost anywhere. I do think PH is your problem causing various nutrients not to be absorbed. Marijuana Plants do best with a PH of 5.5 to 6.5 I usually opt for 6.0 in soil and 5.8 in Rockwool. So set up a reservoir (bucket, tub,etc) and adjust the ph, add nutrients, or do not, but start there and always water from the reservoir. I am always around and feel free to ask anything you think may help. The only bad questions are the ones not asked. I will ask a friend to drop by and offer his opinion he may see something I did not.

+Rep

 

[hbenz]

cheers wingman thanks a bunch, with the dehumidifier when left off rh gets to 73% possibly go higher but got a bit worried and turned it back on. concerning the trouble im having with my leaves i flushed each 9 litre pot with 10 litres of ph 6.5 water and run off came out at 6.5 is this enough to correct the ph of my soil? and how long before i should feed them again?
thanks for the help wingman

 

[PitViper]

Hben....I water with straight 7 all the time with no nutes.you had no problems up until 3 weeks in boom.plants grew fine correct.Also wanted to ask is that a bottom leaf we are looking at how does the top look.I think you need to test the run off water see what your ph and ppm is you may have some peat decay messing with your ph or some salt build up.And your right clean fresh water never hurts. I try to do it now once a week.I need to water my plants atleast 3 times a week in bloom and 1 will be fresh water.To be honest i dont feed my plants in veg for the first 3 to 4 weeks straight water maybe a touch of
tea at 3 weeks realy light.I try to keep as much salt out as i can up front to hit them hard in bloom.

 

[hbenz]

hey viper yes that is a bottom leaf and yes no problems up until 3rd week bloom i vegd for three weeks aswell. after flushing then giving them a lite feed i checked runoff with a drop kit read 6.5 and also tested soil with a probe read between 6.0-6.5. the damage is changing not sure if getting better or worse-will post pics asap. the top of the plants are fine sum purple showing in leaf stems is this normal? also could pot size be a factor im using 9L pots which are about 2 1/2 gallons some small roots are visible through drainage holes would transplanting into 4 gallon pots be beneficial? any input is much appreciated. thanks for the help guys

 

[hbenz]

 

[Wingman420]

Hben....I water with straight 7 all the time with no nutes.you had no problems up until 3 weeks in boom.plants grew fine correct.Also wanted to ask is that a bottom leaf we are looking at how does the top look.I think you need to test the run off water see what your ph and ppm is you may have some peat decay messing with your ph or some salt build up.And your right clean fresh water never hurts. I try to do it now once a week.I need to water my plants atleast 3 times a week in bloom and 1 will be fresh water.To be honest i dont feed my plants in veg for the first 3 to 4 weeks straight water maybe a touch of
tea at 3 weeks realy light.I try to keep as much salt out as i can up front to hit them hard in bloom.

Valued advice from an experienced grower!

hey viper yes that is a bottom leaf and yes no problems up until 3rd week bloom i vegd for three weeks aswell. after flushing then giving them a lite feed i checked runoff with a drop kit read 6.5 and also tested soil with a probe read between 6.0-6.5. the damage is changing not sure if getting better or worse-will post pics asap. the top of the plants are fine sum purple showing in leaf stems is this normal? also could pot size be a factor im using 9L pots which are about 2 1/2 gallons some small roots are visible through drainage holes would transplanting into 4 gallon pots be beneficial? any input is much appreciated. thanks for the help guys

Great info hbenz and the pics will definitely help. Our wise PitViper has forgotten more growing info than most people will ever know. I respect his opinions and value his counsel.

 

[hbenz]

okay guys heres what i am gonns do i flushed a week ago and gave a a lite feed and given 1 litre of ph 6 water 3 days ago (runoff was at 6.5ph-6.8ph) now i have bought some dolomite lime (have read that good for stabilizing ph + cal, mag aswell) 2moro is nute time and i plan on mixing 1-2 tblsp of lime into each pot by breaking up top 2 inchs of soil then watering in with 3/4 strengh ph 6 nute solution also have got temp 75f-80f lights on and have added a co2 candle which is securely attached to the pole you can see in a picture above between the light shades with exhaust and circulation fans off for half of every hour. have not got a co2 meter but was informed by hydro guy that if i vent the room on regular basis all should be okay sooo guys cheers for your help hopfully all goes well but i am a 1st timer so please dont hesitate in telling me if im doing the wrong thing.

p.s plants are still looking very healthy lots of little buds everywhere (pics on the way). today i bought sum 4 foot coated bamboo stakes with twist ties for support. maybe 1 or 2 plants are shorter than these stakes looking good

 

[hbenz]

also was wanting to know if using a product that is used to flush hydro systems is usable in soil havnt tried this but would like to hear what you guys think. i have seen a product called final rinse which clears chemicals and salt build up in hydro systems would it be effective in soil?

 

[hbenz]

everythings looking good thanks for the help guys this is end of week 6. 4 weeks to go
cant wait fingers crossed no more probs