plant problems 4wk into flowering

[mrmrsdarcy]

first time grower. me and my wife did a lot research prior to starting or first grow. been a constant learning process with many bumps in the road. today marks end 4th week of flowering after 5wks veg from clones we purchased.

we choose to go hydro using a homemade hybrid DWC with top feed. we use a air stone in each bucket with total gal system 25-28 gallons. we bought nutrients from our local hydro store and choose use Xnutrients line of hydro ferts. we set up in our closet with a fan blowing into room from bedroom a/c at ground lvl and a oscolating fan blowing over top canopy back out the room. this has helped maintain a 78-82f temps in room.

were using a 400w hps about 18" above top coloa's and you can see the 4' and 2' t5s in above pic. we knew without maintaining a water temp below 72f wouldn't be good and found out first hand 2-3 wks into flowering.
leaves started to show signs of a problem upon investigation we found root rot starting and a fungas gnat problem starting from the medium them clones were grown in.

more research and trip local hydro store we got 35% grade H2O2 and employed a cleaning and regular use H2O2 to maintain clean system and add Oxygen to our water. rinsed as much of medium out net pots as we could and plants got happy and everything was back on track. we veg another 2 wks and at 5wks veg plants were all almost 2' tall and we switched over 12/12 with new flowering feeding and every thing was great 2 wks into flowering we cut one clone each plant. last sunday a week after we cut clones our lower fan leaves started drastic changes once again and our fungas gnat prob was getting worst so I purchased misquetio dunks to kill their larve.

fan leaves started to get nasty brown dead patches yellowing and eventually falling off. more and more doing this each and every day past week.

even have leaves on few plants looking like N deficiency but not sure

even a few which look like maybe cal/mag deficiencies

current setup as of complete water change yesterday

6 plants all 2 1/2 - 3' tall
start wk 5 flowering
water temp 78.8f
room temp 79-80f
rh 60%
ph checked evy few hrs maintain 5.8 as much as possible
currently using bloom ,bloom fx, micro nutes, ammonia acids according to their feed chart
bud candy 2ml/gallon
ppm of city water after sitting 24hr 500-550
ppm of nute strength 1500-1600

plz help us save our medicine. roots are healthy in net pots not sure extent any dam in medium

All replies are much appreciated

 

[Highpotanoose]

Is that soil in your net pots?
Sorry I don't comprehend well
I see ph is 5.8 which is good for hydro but not so good for soil
Your city water is pretty hard may want to look into getting that down.
Also you want to fill your screen to 75% or a lil more before you flip to 12/12

 

[mrmrsdarcy]

these plants came from clones which was started into a soiless mixture of some sorts which I neglected wash out prior to putting in net pots with cley pebbles ive since then spreyed out what I gently could back when I had pythum problem. gonna get RO system in future for that reason. net was after thought for supporting current set up will use tip in next grow

 

[MikeTbob]

I'd suggest PH lockout or Phosphorus deficiency
Cannabis Plant and Pest Problem Solver - Pictorial

 

[mrmrsdarcy]

Yea after talking with my wife and her monitoring of ph while I'm at work she been keeping ph above 6.0 like 6.25 so after seeing a nute uptake chart I see why 5.8 is they key to proper feeding and hence the prosperous lockout

 

[indica vet]

fungal gnat larvae eat the fine hairs on your root sytem which can show damage which can look like this but usually only when infested.
as roots die so do leaves.

 

[mrmrsdarcy]

Possible infestation is really bad a lot gnats flying out pots as I use top drip feed to rain down misquito dunk to kill their offspring. Hope like hell it kills larve but man the roots in bucket comeing out the net pots look healthy nice n white. I'll have post roots pic tommrow when lights on. Update on plants is still losing leaves progression of dead matter from ones yesturday . Hope foiler feed first aid with some super thrive hormex and bloom sprey.

 

[mrmrsdarcy]

here 2 pic of what roots are looking like.

all 6 plants look great but idk if that makes the infestation plausible source of my problem or is it a ph phosphorus problem.

does anyone know why its a constant battle for us to keep ph below 6.0 right before lights go out take ph too just under 5.8 when lights come on were 6.25 - 6.50?

were still on a downhill slide with fan leaves dropping like flies. foliage first aid hopefully will help correct the problem. anyone have opinions of what my problem is?

 

[MikeTbob]

here 2 pic of what roots are looking like.

all 6 plants look great but idk if that makes the infestation plausible source of my problem or is it a ph phosphorus problem.

does anyone know why its a constant battle for us to keep ph below 6.0 right before lights go out take ph too just under 5.8 when lights come on were 6.25 - 6.50?

were still on a downhill slide with fan leaves dropping like flies. foliage first aid hopefully will help correct the problem. anyone have opinions of what my problem is?

My guess would be that is the time when your plant is uptaking juice and that could be enough to cause changes in the PH by itself.

 

[Granny Evie]

I have similar setup, but no gnats or root problem and my leaves are showing same yellow creeping in. I too am struggling to keep 5.8 pH.

 

[mrmrsdarcy]

what about sodium build up from my city water. I assume all white powdery crap on my clay pebbles and buckets is sodium build up. can anyone confirm this?

 

[mrmrsdarcy]

from what ive researched farther into flowering we go our plants run out N and your gonna see a lot yellowing in fan leaves but what im experiencing isn't the plant using up all N yet its something else. hopefully yours isn't doing the brown look of death like mine are

 

[indica vet]

this is just a stab at an explantion for ph shifting so quickly , but being a horticulturist by trade i know for a fact that all living plants dont just draw in water and nutrient with there root system ...they also past waste out through the roots aswell .
now that being said ,with dwc there are a heck of a lot of roots in the res tank its just a thought but perhaps waste from the plant is spiking your ph??? maybe total drains and cleans might have to be stepped up...maybe pathogens that thrive on the waste are affecting your plants????

 

[mrmrsdarcy]

very interesting, thanks for that input. and yes possible pathogens have survived my constant 35% H2O2 I give my resivior every 2-3 days I add 10ml. my problem with my set up is I cannot totally get all water out when I change water. my guess is 1-2 gallons remain once pump starts sucking air.

now I am bewildered that out of all the many first time growers mistakes and blunders that no one has actually seen or come across a plant problem like mine. I value each and every comment and it has helped me assess things but I still don't know whats going on. can anyone address my issue.

 

[budstud]

Your ppm's are to high, plants aren't large enough for that much, you should bump it down to about 800 and see if you get improvement.

https://boards.cannabis.com/attachm...sted-leaves-some-tips-curled-down-phchart.jpg

 

[mrmrsdarcy]

quick update on my plants. top colas and leaves look great appears that the browning and wilting fan leaves has slowed down dramatically and I'm hopeful that problem is fixed. now I have another problem to address and I hope it is a cal/mag problem.

here pic 6 day ago when I started this thread. the 2nd pic is same leave today.

and another leaf from same plant only my 2 grapefruit diesel are having this problem

from mixing up a nice strong dose 35% H2O2 and spraying my clay pebbles 3 times a day I no longer see the gnats flying outta my net pots. what a relief and hopefully I can get whats going on with grapefruit diesel under control. can anyone confirm what deficiency that is?

only 3 weeks to go hope they finish strong