Hey guys! I'm a new grower so sorry if this is a stupid question. What could be causing the leaves to curl down like this? This plant also has a nutrient deficiency that I'm having a hard time diagnosing. It appear to only be the top half of the plant. Any help with this issue would be greatly appreciated. The strain is Cinderella99, I'm growing 8 plants under a single 600W LED (until I'm ready to move them outside). None of the other plants have been experiencing this curling or deficiency in the same way and I take care of them/feed them pretty much the same. The only thing I THINK it could be is that the plant is too close to the light, as this plant I kinda screwed up the LST of it and not it looms taller than the rest
They are clawing. This happens due to Nitrogen toxicity. Second picture looks like Magnesium lockout; too much Potassium (K) can cause this issue. You need to lower the amounts of fertilizer. Possibly a flush is in order. I would also check the media's pH.
Hmm... so I'm using grow/bloom/micro by advanced nutrients but at 1/4th- 1/2half the dosage, so I should just be using less or less often? Normally every fourth watering I give it just water
Hi again @yunghaiku ok let's diagnose some more. Before I do that though, what is the media? soil? coco? And, what is its pH? I the solution's pH and the media's (ie.runoff) pH? Have you been feeding to ~30% runoff? The solution's and runoff's EC would also provide valuable data. As well, what is the water source? Is it tap water? Is the tap water hard or soft, city water? or reverse osmosis water? Are you also adding calmag to the three parts... oh AN :/ I've not used those, but the NPK ratio is what you need to be aware of. (maybe still too high N). I am being serious with these questions. If you do not know, or don't have the equipment, I strongly advise purchasing the required pH and EC meters. I also suggest either a quantum meter (expensive), a (Dr.) Lux meter, or at least download a phone lux app to gauge the amount of light the plants are receiving at the canopy, around the tent, etc. This will tell you if they are too close. I suspect you are growing in a peat based media, but maybe not feeding to runoff, or inappropriate pH, and that there are excess salts accumulating even if you just feed it water every fourth day. Many people feed then water on alternate days (or as required) but I advise using meters and start monitoring the runoff values. Yes, its tedious, but you will learn how to use the nutes this way. Also, some plants (even if the same strain) react different to the (same) nutes. Different plants may mean different fertilizer requirements. The shriveled, twisted new growth is also indicative of a (too) high EC. You might need to flush your media, but I would start only after collecting the mentioned data.
and then there's that too. And the possibility of it being rootbound also exists. sometimes the basics elude me
The positioning of the plant under the sun may affect the curling of the leaves. Also, be sure no to over water it and check the ph of your soil. You can avail of the ph tester online if you can't find one. Normal ph is 6-7, anything above is acidic.
wrong. The lower the pH, the more acidic is the environment. The pH in your stomach is about 2 (very acidic), vinegar's pH is about 4. Above a pH 7.0, the environment is alkaline/basic, like those containing alkali and alkaline elements (Na, Ca, K, etc, not hydrides!). Cannabis is an acid loving plant, likes pH 6.0-6.5 in soil and peat (close to 6.0 in peat and arguable), but likes even lower in hydro at ~5.5 (again, debatable, depends what where which how). I also don't know about position under the sun stuff. But hey, I make mistakes too.
Hey thanks for the detailed response man! I'm growing it in soil that's my local garden center brands as for cannabis. This is my first real grow and I already spent around $700 for everything combined so I skipped out on things like a PH meter and have been relying on the fact that the Advanced Nutrients is a "Ph perfect" system (I know this is not idea but money been tight). Normally when I water there is no run off, but lately I've been watering to runoff more often. The water source is tap water that I've left out for ~48 to dechlorinate it. I'm running 8 plants under 1 600w LED right now, but I plan to move them outside next week when the weather is better at night (still cold here in Canada some nights). It's also possible they're rootbound but I can't transplant them until next week at the earliest. So other than measuring the PH and EC, you recommend watering next time with straight water until there's lots of run off?
This is an essential. I used to use 2x cheap meters and take their average, but I decided to invest in an Apera for ~$100. Its a nice meter, easy to calibrate, and the probe is replaceable, so not a large donation. The cheap meters, they last 6-12 months, and you never know with those things. Another way to go about it is to use color indicators; I don't like litmus, but you can get some less expensive drops. I don't want to diss anyone, but I generally veer people away from AN nutes; they are not pH perfect at all and quite overpriced. I've used many lines and still to this day am learning more. Canna nutes have a good reputation and are much more affordable. The least expensive nutes are Plant Product MJ line if you can get them in the smaller sizes. Megacrop works for many people. And then there's the one=part MaxiBloom if you don't mind GH/monsanto... chloramine will not evaporate, and many municipalities use that... so still has chlorine. I recently learned that a simple carbon filter will remove 99% chlorine, like the pre-filters to an reverse osmosis system. Not expensive, but still costs money. tell me about it! I've been saying the seasons have shifted, so I'm expecting a very warm Christmas. Saskatoon area myself... well, you really should monitor those values. But always feed to runoff. I suggest watering with a good volume of water + calmag (0.5mL per L). You are in Canada, you should be able to find Plant Products, but, I only use Grow, Bloom, and buy a bottle of Calnesium (calmag...). Oh and the Finisher is nice too. These are all dry components. Also may want to invest $5 for some biologicals, ie. beneficial organisms. Can get some for very cheap now in Canada, like $5 ... I bought 4 packs, but haven't even finished the first pack yet.