Weird leaf disease/pest?

13 posts in this topic

Hello guys/girls,

during my last grow I noticed some kind of disease.
It started in early flowering, with little spots/patches with a silvery shine appearing on one or two leaves.
Then it gradually spreads to all other plants and leafs, resulting in almost all leafs having white, silvery spots.
Eventueally it slowly progresses until each leaf has turned completely yellow.
The moment I noticed I was having "issues", I stripped my plants of the "infected" leaves, leaving almost no leaves whatsoever.
Despite that, the grow finished this weekend, I'll put em in the dark today or tomorrow for a day or two and then cut em.
Originally, I thought it were spider mites; however, I never saw any "webbing", and could not find any creature or bug whatsoever, also not on the underside of the leafs.
No bugs in sight. 
Started a new grow, and now I'm seeing the same on my growing (week 4) plants.
Pics below.
If anybody recognizes this supposed disease or nutrition problem, please... you would be a life-saver...
So thanks in advance.
BTW: I can't seem to post pictures next to one another, so horizontally. Now everything is vertical, sorry bout that, hate it as well

IMG 0135

IMG 0123


IMG 0118

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yup, seems the new grow is affected as well. Damn, not even into flowering yet :(


I'm at a loss here... growing in soil, moisture OK, pH OK, nutes at 2/3 recommendations

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yah, all plants affected


some more pix:


gallery_37008_1668_5582.jpg  gallery_37008_1668_108440.jpg


Does anyone know what this is, and how to solve it? At a total loss here...

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Hello guys and girls,
a new grow, and the same disease... :(
I really don't know what to do anymore.
It starts with leafs looking like this, and then slowly dying:
Please, if anybody has got any clue...

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That's PH issue to me. You said PH is OK but what water are you using? TAP water? Because tap water can be from 7-8.5 I believe, and to test PH are you watering the dirt first and testing the run off? Or just the water it self? Whats your SOIL made of and what NUTES? A lot of NUTES change water PH as well.


I mean here is a a PH problem



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wow, amazing, thanks so much.

That pic is exactly how my plants are looking/starting to look.


I was growing in pots (airpots), watering manually. After nutrients were added, I adjusted pH of the solution to 6.5. I have never measured the run-off...

Medium was 40% dirt(soil), 40% cocos, and the remained perlite and vermiculite (assembled myself). Nutrients Canna Terra Vega and Terra Flores, at half manufacturing strength.

So I only measured the pH of the solution right before I fed it to my plants, so accounted for tap water and nutrient pH changes. But never tested runoff.


This new batch were vegged in pots, same method as above (hence, same results I guess). One week ago they were put in a hydro system (Wilma 4 pot dripper system, recirculating setup).

I kept my feeding schedule roughly the same, ie I made the solution as I would have in the past, and filled the hydro reservoir with that.

Just measured the run-off there, and that was 5.8-6.


So, I guess the solution would be to lower the pH of my reservoir solution? The medium now is the about the same, 50% cocos, 30% soil, perlite, vermiculite, in well-draining pots.

What pH do you recommend? 5.5? Or even lower? Run-off is now ~5.8-6.0.

Should I change the nutrients as well? I figured that my setup now isn't really a "real" hydro setup, just a drip (I hardly get any runoff).


Thanks so so much!!

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Hey man


I think a PH for hydro is 5.5-5.8. But are you using soil in a dripper? Cause that would change a lot. Your PH might be low in that case. Do you test EC? What strain are you running? If it has a GHS grow video it will tell you the proper EC, PH and Nute Ratio.


I mean Id try and get info from someone more experienced with this.


I use organic soil, it has dolomitic lime in it. This stuff balances PH and reduces PH issues. I use tap water with a PH of 7 and have been using Earth Juice grow haven't had any issues yet.

Do you know your waters PH before adding anything?

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yeah there's about 40% soil in there. The drip also isn't running full time, just twice a day for 15 minutes. Supposed to be 2L/h drip, so they get 2 x 0.5L /day.

I guess it isn't a "real" hydro setup...


I measured the pH of my reservoir earlier on, and that was 6.5+. So that was not good. I lowered it to ~5.5, just about limit for soil, and also limit for hydro.

EC values were a little high, I use tap water run through a Britta filter, btw. Original tap pH is ~7.5, after the filter it's 7.0.

I follow manuf. recomm. but with the usual dilution, BUT: there simply are no specifications or guidelines for mixtures of soil and cocos.


And frankly, now I'm wondering myself why did I add soil alltogether? Could have just stuck to cocos. Or hell, mapito.

Because I think that now I've got all the hassle of the hydro and will have euh none of the yield advantages lol


Also, I don't know whether it's better to feed them for example 4 times a day for 5 mins, or 2 times for 10, or 8 for ... etc.

Most hydro setups use freerunning drippers that are on 24/7 (like clay pebbles).

But soil+coco -->> drowned plants


Sigh. :)

Let's try to determine a correct-ish pH first. Also, the older leafs are deep green, all newer growth is very light green. Weird. Another thing, or possibly related. We'll see...


Thanks btw!

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Yeah most drippers I see are running hydroton or coco. It could be that when you are filtering it, you are also filtering out a lot of the good minerals. I see a lot using RO Water, or spring water with a certain PPM and mineral additives in DWC, etc. But like I said I dont really know about Hydro, I just use hand watered dirt, organic hippy style, lol. But essentially what you have is an auto water system, rather than hydro. Being in soil.

SO I wonder if you should treat it as such. I mean Ive never PHd water or checked EC lol. I just mix and pour. Hahahahhaa. But NOOB. And I have pretty decent water that all plants love, and its ph7 where yours is higher. And like I said I only use organic which is more forgiving.


I know the guys in Chat have been nothing but helpful with any noob questions I asked, have you tried pinging them at all? Cause please dont do anything major on what Im saying, theyd know way more than me. I wouldnt want to hurt your baby's with bad advice. 


Hope you work it out, have a good one.

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Hi, its more to do with large ph swings than actual PH.

The best PH for your mix i couldnt tell you ,however one thing i will try to

explain is finding out what your rootball PH is at present.

Lets say for example we have water at 6.5ph then water plant so we get

about 10-20% run off we test this and have 6.0ph, this is 0.5ph more acidic,

we then subtract 0.5 from run off value, 6.0-0.5=5.5ph, we now have a

close result to your rootball ph.

The same calculations are needed if it goes other way you just add and not

subtract this number.

Hopes this helps, and yes come enjoy chat have a smoke and get to know us.


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It doesn't look like any nutrient deficiency I've seen and if it were a ph problem it would mean it's not getting enough nutrients.


From the pictures and your original description of it appearing "silvery" would lead me to say it's a pest, most likely thrips. Do you have any fungus gnats?


You said the first pics were taken from late in the flowering period. When were the others taken and where were they located on the plant? Are you finding leaves like this all over the plant or only in certain areas? If in certain areas, where?

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In gardens, there are certain problems that are beyond our control when it comes to plant diseases. However, there are more ways than you may realize to prevent or at least reduce the chance of diseases affecting your plants. Many times, it can be difficult to diagnose what the disease might be. First, create the best growing environment you can for your plants. This includes putting the right plants in the right place. The soil should be loamy and well amended with plenty of organic matter, namely compost. A healthy, vigorous plant is better able to resist infection. Always keep your garden free of weeds and plant debris, because both provide a breeding ground for certain disease-carrying pests. One can also ask a professional pest controller like Pest Control Fairfield CT for their advice. One can find pest controllers near by them in their area by searching them online or can look for more home-made methods to prevent their plants.

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