detailed information about problems with my plant! ++rep!

first of all, heres some information you might need:
area of grow space is about 12 sq feet with 600w light, a fan on the floor and an rvk 125-a1 extractor fan.
im doing an indoor grow with white widow in 4th week flowering.
temps at night are 18.6c with 55% humidity, and temps in day time go up to about 28-30c with not much difference in humidity - roughly 40-50%.
watering roughly every 2 days with biobloom, topmax, hesi tnt complex, superthrive and plant magic - ph adjusted to 6.5. the ph runoff is about 7, but the ph of the feed going in is about 6.5.
growing medium is soil - biobizz light mix.


i've had a problem with my plants leaves for a while with the plants leaves going rusty and yellow. the problem doesnt seem severe to me and to me i think it is a minor issue. not so long ago, i flushed my plant to see if that would help with the problem but doesnt seem to have really helped. after flushing, i did gradually build up the feed again.
as you can see in the pictures, my plant doesnt seem too healthy. on some of the leaves i seem to be getting some rusty spots on leaves that turn a lighter green/yellow colour. the top of the plant seems more of a pale green with the occasional yellowing between leaf veins and some rusting... the middle-bottom of the plant seems otherwise healthy except from the damaged leaf here and there.

top of the plant:



a few damaged leaves in the middle of the plant:


as you can see, the middle of the plant looks pretty healthy to me:


since noticing the problem i have added hesi tnt complex to the mix (around week 3 flowering) to see if this would help me out with my problems as i stupidly didnt bother adding any veg nutes to the mix (which im supposed to) i have checked the ph runoff and been adjusting the ph of the feed too. its been about a week now and when the new leaves start forming, they are green at first but then gradually start getting a .................
i honestly dont understand how it could be a nute def. when i've used these nutes before and am using topmax and biobloom together (which should give out enough nutes to the plant) one thing i have thought it could be is something to do with the plant needing to be repotted or a buildup of salts in the plant that i didnt fully get rid of last time? i've used these nutes on other grows with next to no problems (and that was before i had a ph meter and adjusted ph!)
nothing much has changed since the last grow to the time i started to get problems with the plant. hopefully i have gave out enough detailed information so i can get a more deffinate answer this time... last time i dont think i was detailed enough for the problem to be understood.

so far i know that:
insects are 100% not causing me any problems.
PH doesnt seem to be a problem.
it isn't wind burn!
i dont think this would be a nute burn..
i'm not overwatering/underwatering.

possible problems it could be:
salt buildup?
is my plant one hungry girl?
could the temps/humidity cause any problems like this?
could there be a nute deficiency, if so, then why now.. i havent had problems with my other babys (lemon skunk)
can a lack of oxygen to the rootzone cause problems similar to this?
light bleaching - can light bleaching cause rusty spots?
another possible thing could be the fact im using water straight from the tap - i can remember having problems before and started to let the water sit, and i think this might have helped one of the problems i had. i'm not 100% sure as i can't remember lol!

i'm just trying to rule out all of the problems it can't be, so then i've got a list of possible problems so its easier for me to see where i could be going wrong!

++rep to anybody that can give me a good answer to my problem!

++rep for anybody willing to help out!

anyone?.....

Stop worrying m8 it's ok u will get a few leafs dying of from 4 weeks flower onwards the plant looks healthy can u put a few pics ov the whole plants

Looks like a magnesium def


Magnesium (Mg) Deficiency is quite common. (Mg) deficiency usually turns the older growth leaves a spotty or blotchy yellow. It will eventually get brownish as it worsens. Usually it starts at the outer edges of the leaf and works it way in. The margins of the leaves may bulge up and the tips can curl.
To correct the problem foliar feed the plants by misting. Add 1/4 – 1/2 tablespoon Epson salt diluted in warm water. Then add Epson salt…. around a 1/2 – 1 tablespoon per gallon of water to your reservoir.
Magnesium defficiency is a very common problem when growing marijuana. The cannabis plant uses a lot of (Mg) and many fertilizers do not provide enough.

max316420 said:

Looks like a magnesium def


Magnesium (Mg) Deficiency is quite common. (Mg) deficiency usually turns the older growth leaves a spotty or blotchy yellow. It will eventually get brownish as it worsens. Usually it starts at the outer edges of the leaf and works it way in. The margins of the leaves may bulge up and the tips can curl.
To correct the problem foliar feed the plants by misting. Add 1/4 – 1/2 tablespoon Epson salt diluted in warm water. Then add Epson salt…. around a 1/2 – 1 tablespoon per gallon of water to your reservoir.
Magnesium defficiency is a very common problem when growing marijuana. The cannabis plant uses a lot of (Mg) and many fertilizers do not provide enough.

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okay, i've just checked my water quality info and have this if its any help:

the water hardness is at 200ppm - this could give me information about the calcium and magnesium my water contains if i understood it!
chlorine @ 0.384ppm
nitrate @ 25ppm
manganese @ 1ug/l
iron @ 13ug/l
conductivity - 2500uS/cm @ 20 celcius.

the reason i've put this up is maybe it might help you determine for sure which problem i have. i know for deffinate that the water hardness ppm i've just talked about, is to do with both the calcium and magnesium!

if this is a mag deficiency, then until i can get some epsom salts... should i use my hesi nutes (vegging nutes) at a slightly stronger strength? i know they contain magnesium and everything else. i've gave this plant two feeds of hesi tnt complex since i've had the problem. should i continue trying to feed it this to see if it helps out for now? (no money or time to get any just yet!)

*EDIT*
forgot to say that my ph was quite high before (7.5ish) and i've just started to adjust it.

can somebody tell me if plagron lightmix is any more stable than biobizz lightmiz? i used plagron in my first grow with no problems.. am using biobizz lightmix now and getting a mag def... i didnt get any problems like this when i used plagron!

People don't recommend this during flowering but I have never had a problem with taste or anything like that but a quick way to feed these lovely ladies is to cut your normal dose of veg food in half and foliar feed, but check on the bottle to make sure that you can foliar feed with that type of food. And epsom salt works good but you should think about adding calmag to your normal feedings everytime. GREAT INVESTMENT and remember more food can do more damage.... Sorry one more thing, there is a product called SEA-MAG that is just magnesium if you use that you won't have to worry about od'in on calcium

max316420 said:

Looks like a magnesium def


Magnesium (Mg) Deficiency is quite common. (Mg) deficiency usually turns the older growth leaves a spotty or blotchy yellow. It will eventually get brownish as it worsens. Usually it starts at the outer edges of the leaf and works it way in. The margins of the leaves may bulge up and the tips can curl.
To correct the problem foliar feed the plants by misting. Add 1/4 – 1/2 tablespoon Epson salt diluted in warm water. Then add Epson salt…. around a 1/2 – 1 tablespoon per gallon of water to your reservoir.
Magnesium defficiency is a very common problem when growing marijuana. The cannabis plant uses a lot of (Mg) and many fertilizers do not provide enough.

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I agree with max here, I had magnesium deficiency recently, same symptoms though mine was more pronounced, yours isnt so bad at the moment. however, I would recommend Botinicare cal/mag over Epsom Salts, better for your plant.

Good luck mate! Your plant looks great!

cheers for the help.. so foliar feeding hesi might help my plant? i'm in 4th week flowering - will this cause any budrot/mould?

the problem has been the same for about 1-2months but hasnt got any worse!

could my problem have started where i changed my soil from plagron lightmix to biobizz lightmix?

@Razztafarai - i'm hoping to yield 300g dried off this baby, hopefully i can still get that after the mg problems i've had. just upgraded to a 600w hps too so my yield should be better than the first time round!

looks like a mag deficiency to me too, and if i remember correctly white widow is a mag and N glutton. dont over do it, but after giving the cal mag to supplement, start adding a bit more N to you regular feeding schedule.

I believe your showing a Mag deff too. You know this late in the game the plants go a little Mag deff. MG soil for some reason does it about week 2 of flowering and I gotta do a fert with a TBL SPN Epsom Salt(Magneseum Sulfate) what your plant needs. But really its a sign the plant is using food, normal if not fed.

EDIT - I wouldnt use CalMag because it has calcium in it. Dont treat for issues that dont arrise. Buy calcium seperate so you have a wider range of fixes.

TheTokingKing said:

I believe your showing a Mag deff too. You know this late in the game the plants go a little Mag deff. MG soil for some reason does it about week 2 of flowering and I gotta do a fert with a TBL SPN Epsom Salt(Magneseum Sulfate) what your plant needs. But really its a sign the plant is using food, normal if not fed.

EDIT - I wouldnt use CalMag because it has calcium in it. Dont treat for issues that dont arrise. Buy calcium seperate so you have a wider range of fixes.

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so do you agree it will be safe to use a foliar drench on my plant @ week 4 flowering?

i was gona use hesi tnt complex and superthrive

If you want to know what I would do I would fertilize next time with a 1/2 teaspoon of plain old epsom salt with what you normally do, pst....a tbsp of mollassos and the epsom salt in a gallon of water will work great!

EDIT - Your problem isnt to bad right now so a large adjustment isnt nec.c Watch how you add it and do it only once and let it go several waterings to see the difference. I use a tbsp of moll. in every fert, I use 95% real organics, nothing bought from hydro shops their not in my opinion true organics.

TheTokingKing said:

If you want to know what I would do I would fertilize next time with a 1/2 teaspoon of plain old epsom salt with what you normally do, pst....a tbsp of mollassos and the epsom salt in a gallon of water will work great!

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at the moment i have no epson salts, would my hesi and supervit (foliar fed once) help out until i got the money?

SCCA said:

looks like a mag deficiency to me too, and if i remember correctly white widow is a mag and N glutton. dont over do it, but after giving the cal mag to supplement, start adding a bit more N to you regular feeding schedule.

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i just popped some ww beans, so what your sayin is they love magnesium?

max316420 said:

i just popped some ww beans, so what your sayin is they love magnesium?

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i've heard that too, can't remember where but was reading that the other day... and someone else seems to think they love that extra little bit of food. have just foliar fed with some superthrive and hesi tnt complex... i have some epsom salts on their way to me now so i'm gona have to hope hesi and superthrive help me for now!

max thats exactly what im saying, as a precaution add a cal mag supplement to your feeding schedule every two weeks or so. calcium needs to be added in proportion with magnesium or they become locked out.

SCCA said:

max thats exactly what im saying, as a precaution add a cal mag supplement to your feeding schedule every two weeks or so. calcium needs to be added in proportion with magnesium or they become locked out.

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i've gone and ordered myself epsom salts now.. so is there no point me using this unless i can get a cal supplement for it? would my nutes not contain enough calcium in them?

TheTokingKing said:

If you want to know what I would do I would fertilize next time with a 1/2 teaspoon of plain old epsom salt with what you normally do, pst....a tbsp of mollassos and the epsom salt in a gallon of water will work great!

EDIT - Your problem isnt to bad right now so a large adjustment isnt nec.c Watch how you add it and do it only once and let it go several waterings to see the difference. I use a tbsp of moll. in every fert, I use 95% real organics, nothing bought from hydro shops their not in my opinion true organics.

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^^^ ditto that ^^^


You mentioned that you recently had high pH... 7.5. In that range, many of your micros aren't going to be processed well... if at all. This would make sense with the cal/mag/iron/etc not being available to the plant. And if the pics aren't misleading me... most of your issues are up top (newer growth) that is closer to the light, which is where your micros will often show up. That last pic you had made the plant look in pretty good overall green condition, except as you moved up, which is where the earlier sets of pics appear to have come...?

Anyway, bet that is the real culprit... the super high pH. Adjust that, and the micros will become available again.

And epsoms are at the local grocery store in the pharma section... hella, hella, hella cheap. Do a pinch or two in a gal of water & foliar spray it for a quick dose of magnesium sulfate... but i'd just use your base hesi mixed to .25 ec, pH'd, and lightly mist w that for a quickie boost. Peace

guyson said:

i've gone and ordered myself epsom salts now.. so is there no point me using this unless i can get a cal supplement for it? would my nutes not contain enough calcium in them?

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your nutes should contain enough calcium, but get a calcium supplement in case they start to get out of balance.