Something to worry about?

[Jdsurfer]

Hi guys,

Cyco - Coco and perlite
Canna nutrients A & B, Cannazym, PK 13/14
300w full spectrum LED - 18/6 schedule
2 small fans for air circulation as well as cupboard door left ajar for fresh air supply
Temp typically sits at around 25° C
Unknown humidity levels - still need to get a reader
pH 5.5-6.0
Water every 3 days
Overall a relatively budget setup as I'm inexperienced and do this for self sustenance/the heck of it.

I recently acquired two seedlings that were approx. 3 weeks of age from a guy who had grown them without any nutes whatsoever, in some random soil, and with only natural light... They came to me in pretty thin and wispy condition so I was iffy about rehabilitating them (see pic). This is my 3rd ever grow and the previous ones were with clones so I'm not too sure of any differences in the process.

Anyways, I've noticed that they've grown incredibly dense with very short internodes, leading to a lot of the new leaves twisting into each other and I'm assuming very little light penetration into the lower canopy. They seem to be increasing in height relatively slowly and instead just bushing out. I honestly have no clue what strain these are as I live in NZ (still illegal here) and you get what you get. They're definitely autoflowering as I haven't changed the light schedule and they've begun. I'm thinking the sudden introduction to relatively intense light as well as nutrients has led to the plants growing like this? I'm too scared to train the plants since they were so weak and I don't wanna screw it up.
Canna nutrients say they're okay to use the same dosages for both veg and flower, however, with the previous grows I was getting burnt tips and clawing leaves so had to reduce dosages to less than half of the recommendation on the back of the bottle. I'm yet to use PK on these two plants as they've only just started producing their female sex organs so transitioning into flowering.
As you can see, the bottom leaves of the plants are drooping quite badly whereas the top ones are standing up and almost curling inwards, could this be due to lack of light for bottom leaves? Or is it an issue with nitrogen deficiency due to them not being provided any before I took them in? 2 of the lower early leaves have turned yellow and I plucked them off, but I've noticed over the past day or two that some of the newer leaves are getting burnt tips again so I'm not so sure of nitrogen deficiency anymore? Could potentially be overwatering as I got a little desperate thinking they'd need more after their severe deprivation, but I thought that would effect the upper leaves as well? I've left them for 4 days without water and these pics are immediately after I watered them. I'm not seeing the bottom leaves perk up at all, only staying as is.

Does anyone have any clue as to what this could be and if it's something I should be worried about?

Thanks for any suggestions/help

 

[Mars Hydro]

You grow soil, the ph should be around 6~6.5, and using led grow lights, you might need more cal and mag. The plants looks nice to me though. But maybe others can help.

 

[Papageno]

Your light does look far away...but I think you have a pH issue. Can you measure your runoff? I think you are low.

If leaves are not useful anymore because of light penetration the result is different. They get scavenged to use the nutes higher up.

Nice though so far.

 

[Jdsurfer]

You grow soil, the ph should be around 6~6.5, and using led grow lights, you might need more cal and mag. The plants looks nice to me though. But maybe others can help.

I'm using Cyco - coco coir with perlite mixed in, they were originally in soil but as soon as I got them I transplanted to coco so it'd be compatible with my nutes. At least they look good to you though, that's a relief haha


@ VilliageIdiot:

The light is pretty cheap and produces a lot of heat so I raised it to stop any sort of heat stress.
You're probably right as I use the same pH test kit as I do for my fish tank haha so it's not actually a digital reading but a colour one. It's more or less guess-work below 6 as that's as low as my kit reads. The nutes alone usually take the pH down to the 6-6.5 region and then I'll add a drop or two of phosphoric acid to lower it a bit more. My past two grows were with the same methods and I had issues but the buds were the best I've ever had.
Do these symptoms look like the pH could be too acidic? Looks like I'll be investing in a proper pH reader then haha

 

[Emilya Green]

Sorry Sara, but this is a coco product, and the hydro pH range is correct for this medium.
JD, I don't see a problem, but it would have been good to see the damaged leaves while still on the plant so we could see what it looked like. You are running a proven system and should not have much trouble, but maybe you are seeing a deficiency, and magnesium is very common... but again, i would have to see some damage to make that determination.
Regarding the bottom leaves drooping a bit, I am wondering if you could be a little rootbound... but she doesn't seem to be complaining too badly because what really impresses me is what the top is doing! Those leaves pointing up at the light are the most happy expression these plants can make! The plant is in full transpiration and has increased the surface area of those leaves so as to catch the breeze and be able to evaporate the most water possible... and this produces the suction the plant needs to draw in the last of the water in the coco.
There are two ways to work in coco... you can treat it as a soil and do exactly as you are doing... let it drain all the way to the bottom and by doing so draw oxygen in from the top down to the deepest roots at the bottom of the container. This is why your plants are happy... you are doing it perfectly!
The other way to use coco is to water the container twice a day, keeping it constantly wet and nourished, basically treating it as a small hydro operation. When you do it this way it is necessary to add oxygen, either to the water applied or with an airstone in the container.
The pH range is exactly what you are working with, 5.8-6.1, and if you adjust to 6.1, the coco pulls it down through the range... again, proof is in the pudding... don't change a thing.

 

[Papageno]

So pH is a thing...probably the most important single thing in nutrient uptake. I think I am a fool growing on a cheap pen that only has one digit after the point... and I grow organic where it doesn't really matter. The reason is I want to see good pH anyway is to get great uptake so I still care.

If you are feeding well and see general defficiancy eithe pH is whack. Or you have an infection...something possibly on some mediums real bad temps. I think I have that right now.

Some usefull info...

Nutrient_Uptake_and_pH1

• Papageno
• Dec 20, 2015

CC guides

• Papageno
• Feb 16, 2015

 

[Jdsurfer]

Thanks everyone for all the replies so far:

I've just discovered something a little worrying that may give a better diagnosis of potential issues...
One of the leaves looks to have just shriveled up and wasted, a lot of the tips are starting to brown too and I'm scared I've just overdosed them on nitrogen

This is right at the bottom amongst the droopy leaves

 

[Emilya Green]

Thanks everyone for all the replies so far:

I've just discovered something a little worrying that may give a better diagnosis of potential issues...
One of the leaves looks to have just shriveled up and wasted, a lot of the tips are starting to brown too and I'm scared I've just overdosed them on nitrogen

This is right at the bottom amongst the droopy leaves

very common and pretty much confirms a magnesium deficiency. Get some calmag+

 

[Jdsurfer]

very common and pretty much confirms a magnesium deficiency. Get some calmag+

Awesome, thank you very much for that. Will do ASAP

 

[Jdsurfer]

Hi everyone, just wanted to post an update and also inquire about something...
The plants look good... I think? Still a couple of leaves gradually yellowing and some of the tips a bit burnt due to the magnesium deficiency which I'm currently treating. The only thing is that they seem to have slowed a little in growth, I noticed approx. 1 week ago that they had started to develop the little calyxes but no pistils are protruding as of yet. With my previous grows, the pistils were fully formed by this time, these are autoflowering which I've never grown before but considering the calyxes have formed I'm guessing it will have already initiated flowering and verify that these are autos as the light period hasn't changed?
I've read that autos are typically quicker than photoperiod strains to develop but it's not necessarily seeming that way with these. Any thoughts? Could it still be magnesium-related?