browning/yellowing on leaf edges

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I have checked the plant problems thread but im still unsure what this can be. was hoping someone can look at the pics and help me pinpoint better.

So a little info:
This is week 6 of flowering.
Growing in FFOF soil.
Water gets ph'd around 6.5 before feeding/watering.
temps are 75F-80F.
under a 400w HPS
Feed every other watering with 1tsp molassas, 2 tsp iguana bloom. 1/2 tsp cha-ching, usually feed 1-2 x a week.
Other plants looks the same, some worse than others.

I thought maybe it was nutrient burn, which it may still be. I gave a good flush of several gallons of ph'd water the other day and couple days later dont really see much difference. I always hear the plant "bounces back" after a flush but didnt really see anything out of the ordinary.

The problem is the yellowing and browning start somewhat together but the browning starts at tips and edges then works its way into entire leaf over time like in pic 3. Its at lower and top leafs.

I did a soil test, which tests NPK and Ph of soil. the NPK of the soil looked good except for N, the reading showed next to nothing for N and the ph was good. P and K looked good.

So Im thinking it may be a combination of N defficiancy and nute burn or lacking a micronutrient. Just wanted to get other opinions on this and maybe someone will see the pics and say "oh that is a classic sign of ____"
Thanks for the help!
 

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speeka

Well-Known Member
:
This is week 6 of flowering.
Growing in FFOF soil.
Water gets ph'd around 6.5
Up or down? If your tap water is below 6.5 ph then ph up, Never below 6.5 in soil!!!!
if you ph around 6.5 & you have been doing this for weeks then you may have damaged your soil & micro flora.
 

citar

Member
Up or down? If your tap water is below 6.5 ph then ph up, Never below 6.5 in soil!!!!
if you ph around 6.5 & you have been doing this for weeks then you may have damaged your soil & micro flora.
tap water is 8+ph so i use ph down to get it to around 6.5. use a liquid ph tester so its usually a greenish yellow before i water or feed.
 

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Member
so i shouldnt be watering with 6.5 ph water? i thought 6.5 is ok for soil? like i said i have to bring it down to 6.5 because my tap is high ph.

didnt really think this was a ph issue with the plant, but still cant figure it out.
 

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Looking at the sick plant guide pics, it looks alot like P defficiany but the soil test said p is good, plus the ferts ive been using are high in p. so
another thing i didnt consider is fungus, since it looks like p defficiancy too and the leaves look like that. although the buds look fine no mold there, just leaves look sick. also my ventilation kind of sucks (oscilating fan only with door opened on light times, closed on dark times), which bad ventilation i think is where fungus thrives and my RH has been pretty high lately too. also have fungus gnats here and there though not alot. :( another reason it could be fungus is i noticed the brown spots on one plant, then weeks later they all have it now, like it spread...but idk im no expert, but being the soil test passed except for N and ph is fine and flushed really good already..so im starting to lean more towards fungus now.

any comments or advice is welcomed. thx!
 

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Member
I still don't know if this is really a fungus issue. after reading up a few things, id say im low on N and using too much phosphorus, which may be locking out some micro nutrients like mg or cal. also the cha-ching stuff ive been using has waaay too much P in it and probably a good idea to stop using it for now or use it in small amounts near the end. im thinking of going with a a more balanced fert I have 10-15-10, what do u guys think at 6 weeks flowering?

oh forgot to mention this is a cindy strain cross first time working with it.
 

stumps

Well-Known Member
Up or down? If your tap water is below 6.5 ph then ph up, Never below 6.5 in soil!!!!
if you ph around 6.5 & you have been doing this for weeks then you may have damaged your soil & micro flora.
Think you need to read up on ph.
 

ConnManyThings

Well-Known Member
I still don't know if this is really a fungus issue. after reading up a few things, id say im low on N and using too much phosphorus, which may be locking out some micro nutrients like mg or cal. also the cha-ching stuff ive been using has waaay too much P in it and probably a good idea to stop using it for now or use it in small amounts near the end. im thinking of going with a a more balanced fert I have 10-15-10, what do u guys think at 6 weeks flowering?

oh forgot to mention this is a cindy strain cross first time working with it.

I think that will put you back on the right track. The cha ching, 9-50-? whatever, is too high in P and make have caused you a nutrient lockout... Remove all dead/damaged plant, continue flushing for about a week and start feeding again with a more balanced nute... a 5-10-5 or something along those lines...
 

citar

Member
I think that will put you back on the right track. The cha ching, 9-50-? whatever, is too high in P and make have caused you a nutrient lockout... Remove all dead/damaged plant, continue flushing for about a week and start feeding again with a more balanced nute... a 5-10-5 or something along those lines...
thx for your reply man +rep
sometimes it just helps to hear something from someone else when all these idea are floating around in your brain. but researching more since i made this post has have narrowed it down and its either a disease (fungal?) or no N/too high P.
 
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