# Rust Spots on Leaves, Leading to Brown Necrosis?



## tokinmarine2008 (Jul 13, 2009)

Alright Everyone, I have some issues right now with a few plants.  The fan leaves are getting these brown rust spots, then turning yellow crispy and brown and falling off.  The actual small branches dont seem to be affected, mainly the fan leaves coming off the main stalk... I have nevr seen this before.  Anyways Here is the list of questions... answered if someone with more knowledge would take a look at give a diagnosis that would be great.  I was thinking Magnesium, and bought some epsom salts, have yet to use though...
SOIL:

How long has this problem been going on? Noticeable the past 2 weeks, seems its slowly getting worse.

What STRAIN are you growing? God Bud, Purple #1, Blueberry, 

What was the establishing technique? (seed or clone?) Clone

What is the age of your plants?4-8 weeks.

How long have they been in the soil mixture they are in now?2-4 weeks.

How Tall are the plants?8-14 inches

What PHASE (seedling, vegetative or flower) are the plants in? Veg, problem started happening in flower, but seemed to stop with one...

What Technique are you using? (SOG, SCROG etc) NA

What size pots are you using? (Include how many subjects to pot)2 Gal 1 plant per.

What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?) Bacto ( Peat moss, and perlite, lime buffered to 5.5-6.5.

What Nutrient's are you using?  All of fox farm nutes.

How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* 1tsp grow big, 2tbls big bloom per gal for veg. once a week. 1tsp tiger bloom, 1tbls grow big, 1/4 tsp of cha ching, beastie bloomz, or open sesame.  then 1/4 tsp of cha ching, beeastie or open later in week all in 1 gal of water.

How often are you feeding? 1 heavey per week for veg. 1 heavy per week for flower, with light supplement later in week.

If flowering, when did you switch over to using Bloom nutrients?

What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect) Veg NUtes

What is the TDS/EC/PPM of your nutrients used????

What is the pH of the "RUN-OFF"? 6.2-6.4

What method of pH test was administered? Using Strips? pH pen? pen and strips

How often are you watering?2- times per week

When was your last feeding and how often are you feeding?yesterday, twice a week.

What size bulb are you using? t-8 flourescents, 600 w hps.

What is the distance to the canopy?flouros, 2 -4 inches.  600 hps about 12.

What is your RH Factor? (Relative Humidity)40-50%

What is the canopy temperature?80

What is the Day/Night Temp? (Include fluctuation range)78-83 day, 68-72 night.

What is the current Air Flow? (cfm etc.) 424 CFM through carbon fliter and hood and out

Tell us about your ventilation, intake exhaust and when its running and not running ? Passive intake, constantly running with filter to scrub air. 24/7

Is the fan blowing directly at plants? Have small fan under canopy for air movement.

Is the grow substrate constantly wet or moist? No

Is your water HARD or SOFT??

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?Tap water

Are you using water from a water softener? no

Has plant been recently pruned, cloned or pinched?NO

Have any pest chemicals been used? If so what and when?Pyrethrins spray, doktor doom. Random times through out the week. 

Are plant's infected with pest's?  Have some spider mites, aphids, but actively taking care of those.  



Anyways, any help will be appreciated and here are some pics of the affected plants to go along with this post...:holysheep:


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## zipflip (Jul 13, 2009)

> What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?Tap water


  are you lettin it set out 24-48 hours to evap chlorine by chance?

http://www.marijuanapassion.com/forum/showthread.php?t=43947
check thi link out. i posted a scanned copy page form the hort bible.
  my runoff wit soil is 6.8. maybe ya' bein lower liek ya said 6.2-6.4 is slightly lockin out P...?


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## tokinmarine2008 (Jul 13, 2009)

The Ph of the water after I add my nutes is between 5.8 and 6.  I use ph up to get up to about 6.4-6.6.  I am going to bring the Ph up to 7.2 or so when I water again.  I will check runoff and see.  My run off needs to be in the 6.6-6.8 range then I assume?


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## jmansweed (Jul 13, 2009)

looks likes Phosphorus deficiency - which is uncommon however. Potassium could be more probable. Plants suffering minorly can look vigorous, even taller than average, but tips and edges of leaves turn tan/brown and various necrotic spots develope. Severe damage will result in various hues of colors appearing at viens and growth can slow resulting in low productivity.
Liquedfied kelp, bloom fert and wood ash are commonly used to add potassium if this is the issue but there are a number of great products. Affected leaves will continue to die off but future growth will be corrected. good luck


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## zipflip (Jul 13, 2009)

> My run off needs to be in the 6.6-6.8 range then I assume?


im just sayin that my runoff is always round 6.8 and my water goin in goes in at 6.5 always and im fine. i was just wondering if maybe anyone could elaborate on it all maybe bein lockin out certain nutrients wwhich i believe P is locked out when ph of soil is below 6.5 and gets above 7.0 as well as it startin to lock other stuff too.
there a chart sumwhere on here but i got it saved here. quicker for me to find that way for ya lol.
 also wat kind tester you usin ? cuz if ya usin a tester thats not accurate like one them check the colo ones or the test strips especially those will mostly be off up or down a bit.  also even if you have a digital tester make sure its clean and callibrated. bein dirty can throw ya results off as well.  also if ya tester doesnt compensate for temp of solution your testing, that too could throw it off meaning your tester says 6.4 it could really be lower or even higher.
 and accordin to the chart it does say p is locked out below 6.5 in soil growing


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## tokinmarine2008 (Jul 13, 2009)

I am using a milwaukee Ph tester.  I cal it every time before I use it.  That does make sense though.  If my runoff is around 6.2-6.4 then it makes sense that P is locked out.  I am going to water with a higher PH and see if i cant get my runoff in the 6.6 range.  BUT why is this only happeneing to select plants in my garden.  they all get the same thing all the time.  But yet, its only probably 5 or 6 plants that are like this outta of 50.


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## zipflip (Jul 13, 2009)

are they all the same strain? i have 7 of one strain and 3 each individual different strains i got from random shwag bags. and each diff strain ive noticed prefer more and some less. maybe the ones experiencin this are P lovers and wantin more P? 
i still would say for sure its P tho. i mean dont take my word for it but if it were me an i had to take a crack at it. thats wat i would guess. but also ya really have to figure wats cauzin the def like sometime ph fluctuation or bein off locks out certain nutes as the chart above explains, or the deal bout diff starias wit diff needs etc etc. so simply addin more P wouldnt be my first step. but i would think P is bein locked out for some reson.
oh ya never really said if ya let the tap water you use set out first to evap chlorine.
also wats your tap water like PPM-wise. i know my tap even when left to sit over nite teh PPm's are still too hi to use imo. which can also cause certain nutes to lock out. the ppms of my rain water here  were too hi as well when i finally checked it.
also i thought i was sittin on top of heaven when i collected 20 plus gallons rain water in tubs in my yard. i went on usin it for whle until my leves startin goin a tad funky below. then i went back to my origial use of RO watrer ad all was well also.


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## tokinmarine2008 (Jul 13, 2009)

I have always used my tap water right from the faucet.  I do not know the ppm of it though.  Yet another reason this could be happening.  The strains its affecting are random, and just random plants.  None of this has happened before, the only thing I changed was from FFOF to this bacto. (peat moss, perlite and lime)  I have a feeling that with the run-off being low and everything you have said Zip that P is the source of my problems.  I will let my water sit out and bring the Ph up of my nute solution when watering.  Its just funny to me becuase on the plants it affected , the new growth is fine on 90 percent of  plants.  I was wondering if possibly Humidity could also have something to do with what started to cause the rusty spots.  I dont doubt its P, not one bit, it just seems weird that i would only notice it on some plants.  So does this mean that i need to start checking the runoff of all my plants? if thats the case that just wont happen.  ill throw bad ones out before spending all days checking  plants runoff, when the others are doing fine. Haha.  Thanks Zip


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## zipflip (Jul 13, 2009)

weather you've noticed bad effects of usin tap on ya girls or not it wont hurt to leave set out in advance even 48 plus hours to evap the chlorine.  it could very well be that ya changed media(grow mix) and that in combination wit the tap an chlorine is doin it all.  i mean like ya said ya never had probs before usin strait from the tap.... 
  also local tap water can change as far as PPM's over the course of time dependin on the water goin in to be treated and hopw much of wat chemicals they use to treat it. i kow so may on here talk of how they tap fluctuates in PPM's thruout the course of a year  durin certain seasons or watever...
  sorry, im not tryin to overload ya here wit food for thought . just tryin to make sure wit ya on ay prob first an i see later on that you had major melt down tryin to address it in a wrong way etc... lol
    anyone else out there care to agree or disagree or add to anythin ive put out there for tokin?


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## tokinmarine2008 (Jul 13, 2009)

There are probably 5 different strains, right now that have some plants unaffected and some affected.  Both in same medium, getting same nutes, same Ph.  Why would it be that just some of the plants are showing this?  Wouldnt it make more sense that all would show?  Granted the spider mites or aphids and pyrethrins to treat cant be good for them either....  Should i flush with PH'd water to raise the soil Ph??? Or should i let them dry then flush?  I just feed fairly heavy yesterday.....


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## zipflip (Jul 13, 2009)

i do believe that the more sativa phenos are usually not as hungry as most indies are.  from wat i have noticed wit havin both sat dom and sat indi cross lookin strains and strait indie dominant strains that the indies tend to be more pigs when comes to eating vs sat's.  could it be your strains differ in that aspect ..?
  like say the ones affected are more indi vs ones not affected bein more sat's?


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## tokinmarine2008 (Jul 14, 2009)

Well i was actually thinking the same thing, but it is happening more to the indies than the sativas.  although the sativas do show some wear not as bad though.  Also the newer growth right on top looks ok.  I fed with a slightly higher Ph the other day than normal, going to continue to do so, and hopefully see some improvement.


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## zipflip (Jul 14, 2009)

> but it is happening more to the indies than the sativas


  exactly... indies  usually from wat i understand require more feedings at higher doses than most sat doms . (ie higher nute levels)



> Also the newer growth right on top looks ok


 nutrient deficiency will usually occur form the botom up from my experience an knowledge.



> I fed with a slightly higher Ph the other day than normal, going to continue to do so, and hopefully see some improvement


 just dont get too happy wit the nutes tho. if it was the prob then you should start noticing results in few days. so wait it out now to feed again  as normal til you notice if it helpin or gettin worse. and if ya keep it small that way when/if ya try correcting it its not a PITA to do so.

just like people.  bigger people eat more smaller peopel eat less and smaller peole may eat more if higher metabolism an vice versa. same wit plants imo.
  sum like one sat i got in my grow is just a finicky and very picky lady to say the least. lol


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## highman (Jul 14, 2009)

was having this problem in a hydro setup checked the water today and it was at 7.1 re-adjusted it to 6.0 so we will see if it helps


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## zipflip (Jul 14, 2009)

> it was at 7.1


aint hydro suppose to be lower than soil tho? like 5.5-6.o

thats prolly your problem there man no matter watit is...
  i nevr done hydro before so i will stand corrected if i am wrong but im almost pos hydro suppose to be 5.5-6.0 or close to it.


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## highman (Jul 14, 2009)

mg will not absorb below 5.7 i find 5.9 -6.0 is an optimal number, it gives a little bit of play for other nutes


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## tokinmarine2008 (Jul 14, 2009)

Now, should i add lime to my soil mix?  If the soil Ph is low, that cant be fixed by watering with higher Ph's i believe.  I remember hearing your water ph should be the same as the runoff Ph.  Ideally water with 6.8 get 6.8 runoff, if not then lime needs to be added to mix correct????  Still fairly new to this.  Have used FFOF up until this point.  I find this a lot more challenging, and a better learning experience.  So lime? Yes?


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## zipflip (Jul 14, 2009)

my water goes in 6.5 and runs off at 6.8 and all seems fine wit my girls anyway.


> should i add lime to my soil mix? If the soil Ph is low


 thats wat i did when i mixed my soil.but i also hear people workin a tablespoon or two into the top soil after planted and experienceing probs.  not sure on the dosage/amount of lime to use. but for sure just dont make the mistake of gettin hydrated lime.
  get wats called horticultural/garden/dolomite lime.  hydrated works too fast and hard an can burn the hek out ya plants as i understand it.  
  when i mixed my soil my run off before planting wit it was 6.3 wit water goin in at 6.5 and i added lime and viola.  
  do a serch on here for lime. select advanced serch and select titles insted of posts below the serch term bar. it'll give you all related threads titled wit lime in it..


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