Kratky problems!

This looks like the “leaf problem” from last year.

Wind Burn

From an indoor grow, but it can be pretty windy outdoors here. I wonder what is the pathogenesis here.

It says “not being able to fulfill all its normal processes.”.

That plant in the 12 days ago was one of two that went out in a dwc bucket, in full sun, at about three weeks old. They recovered somewhat, but the White Widow that went out a week or so later looks amazing (to me)! And I learned something.

BTW, the first two seedlings did that rigid stem arcing thing when I transferred the outside again, and this time with decent aeration with astronger pump.

“Week later” out front in the first picture, and is the first one on the far left in the second. The other two look sort of “stretchy”, and a paler green. Hard to believe they are each about five weeks old. I think that might be a nutrient deficiency. I’m using MaxiGro and ppm is about 600. ph about 6.5.

Im no expert but ive been told that ph in hydro or soiless should be around 5.8 if im not mistaken you ph might be to high as well but id ask a few of the pros

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@Josh1126 is right. Optimum ph for hydro is 5.8

Thank you, and I’ve been working on bringing it down. I’ve read 5.8 for veg, but a bit higher for flowering; is that right? I’m also battling a bit if root rot, and winder if that increases the pH. I just started adding hydroguard.

I use hydrogaurd ALWAYS. I don’t think that is correct about the ph. Ask @Donaldj. He KNOWS about ph and nutrients

actually 5.8-6 for veg 5.8-5.6 flower nutrient avail changes in each range lower ph lowers N level raises P slightly reduces Cal and K higher ph increases N Cal K while reducing P § is needed most during bud development K during rooting Cal stretch and top growth N for leaf development

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This year’s grow, and wonder i

f this might be pre-flowering.

hi, i have been following your grow and i have a couple of questions.

looking to go kratky indoor with maxigrow and maxibloom along with clay pellets. we are planning on leaving about 4 inches of space from the top so the roots can manage air. we are dumping all nutrients in at once (maxigrow) for veg and (maxibloom) for flower.

why did you go from kratky to dwc?

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I don’t recall all the specifics, but “everyone” said I’d need more oxygen for the roots. In spite of that, this is how it turned out.

NellaBella you have my respect. Despite all the conflicting well-intended information, you stayed with the grow highs and lows and oh so nearly pulled it off.

My pure Kratky grow started in December 2018 and finished in June 2019.

The end of the grow can be found here.

I did get a crop and achieved my aim of producing enough seeds to be independent. The yield was low and the plants were stunted but they made it through.

During this year, I have carried out several experiments to determine why a pure form of Kratky works so well for lettuce and microgreens but struggles to produce a satisfactory Cannabis crop.

Lettuce and microgreens are a one cycle crop and use up all of the nutrients before finally being harvested. During the growth phase, I found that the root tips barely grew more than an inch in the water at all times with the majority of root mass accumulating in the air space of the tank.

I think the air in the tank is constantly oxygenating a thin layer of water through absorption. The oxygenized layer must play a role in the plant’s ability to take up nutrients while the air-roots keep the whole plant healthy. This leads to a bountiful and tasty crop.

Cannabis is a longterm two-cycle crop (veg&bloom) and seems to require far more root exposure to nutrients than root tips in a shallow oxygenized layer can provide.

In my grow, I needed to top up each Kratky pot a few times during the veg phase changing from two-litre pots to eleven-litre square pots. On each occasion, I filled up to the 2/3 point thinking that the more roots in water would mean nutrient uptake and improved plant growth.

This proved not to be the case. The roots now in the crucial oxygenized layer were further up the root stem and the root tips were in the unoxygenated layer and could not take up nutrients.

That is the reason why my yield was low and the plants were stunted but it is also why they made it through.

I’m in week three of flowering my 2nd grow using a Kratky + air stones + 145-litre tank system and I’m confident that the addition of bubbles and agitation with an increased water surface area has increased oxygen levels and overall plant health.

Good luck with your grows and experiments.


That sounds interesting!

I am trying an outdoor DWC again; this time with an autoflowering WW, so it does not have to be lucky enough to make it through all the high temps, and I don’t have to be paranoid about someone spotting the huge plants outdoors in the fall. I am also doing a regular WW in a self watering container.

I’ve got some mites and some caterpillars.

And some tomatoes!

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Snap, I’ve got Italian Plum Tomatoes growing in a Kratky pot too. They take up at least 1 litre of nutrients every day and that’s with no air stone!

Bergman has some good information about bugs, mites and other nasties.

Mildew and bud rot carried away my whole outside crop last year. That’s why I started a seed breeding experiment to get a super hardy strain strong enough to cope with the North of Ireland’s climate. I’ll know if I’ve been successful by the end of October.

Fingers crossed for both of use.

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Yes, indeed I have read your 2018 Journal.

We both got knocked down last year.

But, we got up again in 2019 to give it another go.

My auto crops were grown early in spring last year and produced a harvest with no mildew or mould by late summer.

Timing your WW Auto’s to mature before the hot season is a smart move and I wish you the very best of luck.

Did you check out this thread? It’s on my reading list lol!

Not yet but, I will

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Them babies are ready for a bigger pot :v:

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Last year my plant was stolen in October. I just read pictures might add GPS, making that easier. Maybe I’ll find a work around.

If I recall the forum strips any location tagging from photos. But yes any digital picture from a phone can have its location taken in it. If posting pictures I would strip the location info first if you turned that on, on your phone. I once had my photos automatically syncing to facebook, that was a issue…

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I believe the leaf problem was thrips,