What's wrong with this fan leaf?

WifeInTheDark

New Member
Hi i have a plant that is showing strange leaf problems, one of it's lower fan leaves is very sick and discolored. It is in potting mix under 200w 2700k, i use cal-mag, and 2-7-7 npk nutes and feed 6.5 ph water, here are some pics of the leaves. What's wrong with my leaf?

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Do you think it looks like Magnesium deficiency?

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I think you have too high of temps coupled with Mag Def. It could be too low of humidity too.

But I am just guessing.

I know you say you are adding Magnesium...but adding stuff and having the plant absorb it are 2 different things. You could have root rot. Another cause would be fungus gnats but you would know that.

If you have not been letting the soil dry out completely before watering again you could have rot in there and that can do a lot of things including messing up the pH. So even though you add it correctly you are adding it to a toxic waste dump and it doesn't matter.


So the solution to that is...

1) let it dry out
2) flush it hard
3) followed by an immediate dose of Beneficial bacteria and enzymes
4) followed immediately by driving it in with some pH'd water
5) making sure all the time all the run off goes down the drain (do this in a sink or bath tub)

Then you let it dry out again. Depending on how you added the bacteria (off the shelf stuff or home brew tea) you may have enough nutes in there to just water for a few weeks and slowly start adding nutes back. If you do a basic off the shelf bacteria it could still be a while before adding nutes back because when you reinvigorate the soil it may unlock all the good stuff that wasn't flushed....and a good enzyme treatment will turn dead rotting material back into plant food.

That is what I call the "carpet bomb reaction"... that basically fixes almost anything that went wrong in the soil. If you have a deficiency and you have been adding it correctly then there is a problem in the root zone and it needs to be reconditioned and that is how you do it.

:goodluck:

Oh and I usually would add a fan to the top of the soil to get it to dry out faster after the treatment.
 
Thank you for your input, i have flushed recently, I always use ph'd water and let the soil dry out completely between watering. The mag deficiency was fixed with cal-mag, and should no longer be an issue. I have also recently treated for thrips, fungus gnats etc, run off generally runs clear. What do you mean by the beneficial bacterial enzymes? Leaves are randomly dying off and falling off, I'm getting worried, this leaf just fell off of one of my other plants;

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P.S: These leaves are mostly just lower fan leaves, but some of my girls sill have all their lower leaves and are nice and green. What could be happening here? Is this normal, or is something wrong here? Any opinions and input is appreciated, thank you.
 
This is a good thread on Beneficial bacteria and such. At the very end there is a recipe I use. The warnings about it being strong are only in DWC because the Dose much match the res size but in soil you can just use it. 2-4 cups per plant and drive it in with pH'd water.

Tea Bag your DWC



Many if not most problems that show in a leaf are not fixable in the leaf. You can only look at new growth to see if it is fixed. Many things like nitrogen deficiency take 4-6 days to show in new growth AFTER it has been properly dealt with...meaning you did everything right and for 5 days you have to sit and wait and not second guess yourself.

Fungus gnats live for 1.5 weeks roughly. depending on how you dealt with them you may still have them laying eggs out that far. then you have to deal with the rebound which can take a very long time.

Fungus gnats cause root damage which then causes any kind of deficiency to show. The roots that get damaged are ruined permanently and will not heal so you need to grow new roots. During that period the above ground plant is way too big for the root system so all sorts of problems will start to appear. You will need to wait it our for a new root system and then possibly cut back the plant and start veg all over.


It all depends on how you dealt with it, how successful you were in dealing with it How early you caught it and how healthy the plant and soil was leading into the problem.

Lower leaves failing first is classic signs of soil problems which may include pests. the plant is eating itself starting with the leaves farthest from the light source and will work its way up until the problem is fixed or the plant dies.
 
the temps run between 75F -79F, and the humidity stays around 50, and I use ph`d water of 6.5, (I use a phosphoric based ph down thats 80% strength, and use about 4 drops per gallon to get my ph down from about 8.6).

The first 2 pictures are from the same plant as the first picture I posted.
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And heres a couple pics of the one that lost its leaf (referring to my second post)
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And here are all of them together (most of them have the same problem, but not all)

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ok, i do see some clawing and think that your nutes are a bit too strong for this point of the grow... 2 weeks from now they will probably need the mix you are giving them, but I would back off for now about 50%. That cupping of the leaf margins at the top looks like heat stress ... how big is your light? Is there one close to those plants doing that, because it doesnt look like they are all doing it. Do you have foil or mylar or something up that could be causing some hot spots in the grow area?

I am also curious if you have been giving this 2-7-7 stuff all along, even in veg, or if you just started this for flower?
 
They are actually all together under my diy system . 8 100w, 2700k cfls, with big baking tins over it concentrating the light down, with all the bulbs at the same level and distance away from each other. I also have a mirror off to one side to provide light towards the middle foilage and an aluminum mirror underneath them . I actually just started using these nutrients at flowering start (i heard that nitrogen intake is low during flowering), during the entire veg I had them on 8-14-9, which they loved. At flowering I also started using cal-mag which is 2-0-0. Im curious to what you said about phosphorus overload because, I just recently started using the phosphoric ph down (about a week ago) which apparently after research is 0-26-0 (it works great tho).
 
ok, i do see some clawing and think that your nutes are a bit too strong for this point of the grow... 2 weeks from now they will probably need the mix you are giving them, but I would back off for now about 50%. That cupping of the leaf margins at the top looks like heat stress ... how big is your light? Is there one close to those plants doing that, because it doesnt look like they are all doing it. Do you have foil or mylar or something up that could be causing some hot spots in the grow area?

I am also curious if you have been giving this 2-7-7 stuff all along, even in veg, or if you just started this for flower?

Hey so, How exactly would i go about lowering the amount of phosphorous i give them if i need the phosphoric acid to lower the ph of my water? I do not want to poison them with an excess of phosphorous but they need water and it comes out of my tap at 8.6-9.0...... what should i do??
 
Okay thank you so much for the help and fast responses. I was just worried they were getting excessive phosphorous from the ph down, thanks for the reassurance :)
 
Please consider the last lines in my signature... where I am talking about nutes being vitamins. What I say there has to do with new plants mostly, but it also applies to plants grown in artificial conditions. Nutes can only take a plant that is not under very strong light and enjoying massive amounts of airflow so far. Any additional nutes that cant be used, can start causing problems as they build up in the soil. As your plant gets bigger, it will probably be able to handle what you are doing now, just fine. But now, she is complaining a bit... not loudly, but it does look like she has an issue.
 
They are actually all together under my diy system . 8 100w, 2700k cfls, with big baking tins over it concentrating the light down, with all the bulbs at the same level and distance away from each other. I also have a mirror off to one side to provide light towards the middle foilage and an aluminum mirror underneath them . I actually just started using these nutrients at flowering start (i heard that nitrogen intake is low during flowering), during the entire veg I had them on 8-14-9, which they loved. At flowering I also started using cal-mag which is 2-0-0. Im curious to what you said about phosphorus overload because, I just recently started using the phosphoric ph down (about a week ago) which apparently after research is 0-26-0 (it works great tho).

A master gardener once told me that plants do not like having light coming at them from under their leaves. It confuses them. The mirror under the plants is not as helpful as you may think. The mirror off the to side is probably causing some issues too... you would be better off with a white wall there instead of bouncing the direct reflected light in an unnatural way. Surely there are hot spots within this grow area because of the strong mirror reflected light. I really think you would be better off with a non reflective floor and white walls all around.
 
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