Nutrient burn or deficiency?

[ReefKief]

Hello everyone!
My Lemon Auto has started showing some burning on its first set of leaves. She's exactly 14 days old from sprouting. I was wondering if this is due to overfeeding, underfeeding or maybe heat stress? The last few days have been quite hot and the temps in my grow tent were at 30°C MAX. Usually the temps are about 21°C-26°C. RH is usually 50%-80% now that I use a humidifier.

The soil I'm using is BioBizz Light-Mix and I'm also using BioBizz nutrients. I followed the official BioBizz nutrient feeding schedule so I started giving my plant nutrients during the second week (day 10). Since it's an autoflower, I chose to give it only 1/8 of the recommended dosage. I mixed up 0.25ml of Bio-Grow with 1L of tap water. The PH was 6.7 and the ppm were at 377. I watered my plant with this mixture across 2 days.

As soon as it started showing the burned tips I switched to plain water. I gave it enough water to get a little runoff (for the first time) and the ppm of the runoff was 2100!! I thought the ppm of the runoff should be similar to the ppm of the water/nutes mixture. I'm not sure what is going on, maybe that's just the case for coco and not for soil?

The plant is still growing really fast and the new growth is looking healthy. I'm not sure if I should flush the plant, give it more nutrient or if I should just wait it out. I'm just worried that more leaves might start to get burned too.

I was also thinking about starting LST today but I'm not sure if that is a good idea because of the burning of the leaves. What do you guys think? Would LST stress out the plant even more?

Let me know what you guys think.

BTW I'm using a full spectrum LED light. It pulls about 110W.

Thanks in advance

 

[Emilya Green]

hi @ReefKief and welcome to the forum!

That looks like a deficiency to me. 1/8 the recommended nutes is most likely the problem... this plant is hungry. Look for the special feeding schedule for auto plants, and follow that... if you can find one.

 

[ReefKief]

Hey Emilya thanks for the quick answer!

Unfortunately there isn’t a official feeding schedule for auto plants from BioBizz. I just found some guides on reddit that say to start off with 1/8 the recommended dose.

I'll feed the plant again as soon as the soil has dried up. Maybe I'll try a 1/2 dose next time.

BTW I'm also using your watering guide for auto plants, it has been working great so far.

I appreciate the help!!

 

[Emilya Green]

Hey Emilya thanks for the quick answer!

Unfortunately there isn’t a official feeding schedule for auto plants from BioBizz. I just found some guides on reddit that say to start off with 1/8 the recommended dose.

I'll feed the plant again as soon as the soil has dried up. Maybe I'll try a 1/2 dose next time.

BTW I'm also using your watering guide for auto plants, it has been working great so far.

I appreciate the help!!

Thank you for the quick reply to my reply. I was actually making a sneaky point. There is no official auto feeding schedule for ANY nutrient line! If it were such an empirical truth that autos need less feed than photo plants, you would think that just one nutrient company would have jumped on this and developed the "definitive" auto feeding system... but none have. Makes you want to go hmmmm.

A plant is a plant is a plant. Feed according to its needs, which changes as it gets bigger and/or lights get stronger. It is a myth that autos need less nutrient... logically, a rapidly growing plant such as an auto should need more nutrient than a slower growing photo of the same size.

You just cant believe everything you read online, especially outside of this forum. If your goal is to minimally feed to keep your costs down and your chances of burning the plants to a minimum, and just barely feeding enough to keep your plants alive to be safe, then you must also expect minimal yields as a result of all of your caution. If autos were so sensitive and able to get by on such minimal nutes, then why don't people just use a rich soil and nothing else all through the grow and not even mess with nutes?? It has always been my belief that if you are going to buy expensive nutes in order to make better yields and higher quality product, you need to not be afraid to use these nutes, at least as recommended.

 

[ReefKief]

Since my last grow failed because of overfeeding and overwatering I've been a little paranoid about feeding this plant, but I have to agree with what you're saying. This plant is growing really fast which should make it even more hungry for nutrients.

I'll give her more nutrients from now on and I'll keep an eye on her to see how she reacts to it.

 

[Roy Growin]

I am growing a similar strain in the same soil with the same nutes my friend
New growth looks fine - 0.5ml/L pH 6.3-6.5 for the first feed week is good, but personally I'd start conditioning the soil with some organics (ActiVera, BioHeaven, Humic Acid) too
Once the roots are established the plant's growth becomes vigorous so topping and LST is easy

 

[ReefKief]

Your plant is looking great!
Thanks for the advice.
Unfortunately Bio-Grow and Bio-Bloom is all I have right now. I was planning on giving it 1ml Bio-Grow + 0.5ml Bio-Bloom/L tomorrow to stop the deficiency. This would be 1/2 the amount suggested by the feeding schedule for the 3rd week. I hope it won't be too much and cause nutrient burn.

 

[ReefKief]

I am growing a similar strain in the same soil with the same nutes my friend
New growth looks fine - 0.5ml/L pH 6.3-6.5 for the first feed week is good, but personally I'd start conditioning the soil with some organics (ActiVera, BioHeaven, Humic Acid) too
Once the roots are established the plant's growth becomes vigorous so topping and LST is easy

 

[Roy Growin]

Your plant is looking great!
Thanks for the advice.
Unfortunately Bio-Grow and Bio-Bloom is all I have right now. I was planning on giving it 1ml Bio-Grow + 0.5ml Bio-Bloom/L tomorrow to stop the deficiency. This would be 1/2 the amount suggested by the feeding schedule for the 3rd week. I hope it won't be too much and cause nutrient burn.

Gro + Bloom are not enough on their own, you will need some other options from the BioBizz range to get the best out of them. You don't get nute burn from organics, but you can get excess (N,P) so ignore the charts and just lightly feed as you see fit until full bloom - that's a bit of a game-changer as you can pump it up then

 

[Emilya Green]

This would be 1/2 the amount suggested by the feeding schedule for the 3rd week. I hope it won't be too much and cause nutrient burn.

Most people when seeing a slight little triangle of tip burn, automatically think that OMG, I am overfeeding, when nothing of the sort is happening. The online gurus love using this though, convincing newbies that they need to listen to their every preaching, because they are burning their plant! The gurus all warn, you need to feed at 1/4 strength, and sure enough, the now hungry plants no longer display this indicator. Does this mean what it seems that it means... that there was a problem and now it is gone??

Look at this picture... this is my current grow. Notice the tip burns.

I would bet that I could easily find 20 people who would advise me that I am burning my plants... that I am overfeeding. The problem here is that technically, I am not feeding these plants. They are being grown organically in @GeoFlora Nutrients and the microbes and the plants are working together to determine how much nutrient to bring to the roots, and I have nothing at all to do with it. This is nature, doing what nature does. I asked my AG professor friend this question... why are the plants burning themselves??

He explained that this is not a burn and that the plants send a signal down to the roots, to the microbes, that they have had enough of a particular food for now.... thank you very much. What happens below, also happens up above in the leaves, and we see this indicator at the tips of the leaves. It very much looks like a burn, doesn't it... but it is not.

There is an adage in the pot growing world... "If you aren't at least burning the tips, you aren't trying hard enough."

 

[ReefKief]

Most people when seeing a slight little triangle of tip burn, automatically think that OMG, I am overfeeding, when nothing of the sort is happening. The online gurus love using this though, convincing newbies that they need to listen to their every preaching, because they are burning their plant! The gurus all warn, you need to feed at 1/4 strength, and sure enough, the now hungry plants no longer display this indicator. Does this mean what it seems that it means... that there was a problem and now it is gone??

Look at this picture... this is my current grow. Notice the tip burns.

I would bet that I could easily find 20 people who would advise me that I am burning my plants... that I am overfeeding. The problem here is that technically, I am not feeding these plants. They are being grown organically in @GeoFlora Nutrients and the microbes and the plants are working together to determine how much nutrient to bring to the roots, and I have nothing at all to do with it. This is nature, doing what nature does. I asked my AG professor friend this question... why are the plants burning themselves??

He explained that this is not a burn and that the plants send a signal down to the roots, to the microbes, that they have had enough of a particular food for now.... thank you very much. What happens below, also happens up above in the leaves, and we see this indicator at the tips of the leaves. It very much looks like a burn, doesn't it... but it is not.

There is an adage in the pot growing world... "If you aren't at least burning the tips, you aren't trying hard enough."

Well said! Thanks for the info.

 

[Ghostwriter31]

Most people when seeing a slight little triangle of tip burn, automatically think that OMG, I am overfeeding, when nothing of the sort is happening. The online gurus love using this though, convincing newbies that they need to listen to their every preaching, because they are burning their plant! The gurus all warn, you need to feed at 1/4 strength, and sure enough, the now hungry plants no longer display this indicator. Does this mean what it seems that it means... that there was a problem and now it is gone??

Look at this picture... this is my current grow. Notice the tip burns.

I would bet that I could easily find 20 people who would advise me that I am burning my plants... that I am overfeeding. The problem here is that technically, I am not feeding these plants. They are being grown organically in @GeoFlora Nutrients and the microbes and the plants are working together to determine how much nutrient to bring to the roots, and I have nothing at all to do with it. This is nature, doing what nature does. I asked my AG professor friend this question... why are the plants burning themselves??

He explained that this is not a burn and that the plants send a signal down to the roots, to the microbes, that they have had enough of a particular food for now.... thank you very much. What happens below, also happens up above in the leaves, and we see this indicator at the tips of the leaves. It very much looks like a burn, doesn't it... but it is not.

There is an adage in the pot growing world... "If you aren't at least burning the tips, you aren't trying hard enough."

Shit this is exactly how my leaves looked and I thought I had the lights to low, I have a different perspective now

 

[ReefKief]

Most people when seeing a slight little triangle of tip burn, automatically think that OMG, I am overfeeding, when nothing of the sort is happening. The online gurus love using this though, convincing newbies that they need to listen to their every preaching, because they are burning their plant! The gurus all warn, you need to feed at 1/4 strength, and sure enough, the now hungry plants no longer display this indicator. Does this mean what it seems that it means... that there was a problem and now it is gone??

Look at this picture... this is my current grow. Notice the tip burns.

I would bet that I could easily find 20 people who would advise me that I am burning my plants... that I am overfeeding. The problem here is that technically, I am not feeding these plants. They are being grown organically in @GeoFlora Nutrients and the microbes and the plants are working together to determine how much nutrient to bring to the roots, and I have nothing at all to do with it. This is nature, doing what nature does. I asked my AG professor friend this question... why are the plants burning themselves??

He explained that this is not a burn and that the plants send a signal down to the roots, to the microbes, that they have had enough of a particular food for now.... thank you very much. What happens below, also happens up above in the leaves, and we see this indicator at the tips of the leaves. It very much looks like a burn, doesn't it... but it is not.

There is an adage in the pot growing world... "If you aren't at least burning the tips, you aren't trying hard enough."

UPDATE:

I've been feeding my plant 1/2 the recommended nutrient dosage for the past week and the burning has spread to the upper leaves pretty quickly. The growth has slowed down too. I'm worried she won't make it if I don't fix the issue soon...

What could it be? Is it still a potassium deficiency or something else? Maybe a nutrient lockout? I'm a little confused since I thought nutrient lockouts don't happen with organic nutrients. I was planning on flushing the plant but I'm scared it might stunt the plant even more.

The last few days have been a little hotter at about 30°C, maybe that's the issue? Humidity is at about 50%. Soil and runoff PH are about 6.5. I used 1ml BioBizz Bio-Grow + 0.5ml Bio-Bloom/L to feed her. I saturate the whole pot until I get a little runoff and I leave it like that until the top layer of the soil is dry again.

I really don't know what I'm doing wrong. Is she still going to make it in your opinion?

Thanks in advance

 

[Emilya Green]

It has nothing to do with nutrients... you are severely overwatering. Please look up the "lift the pot" method of determining when to water. You might also want to read my article on how to properly water. You are watering way too often and are drowning your lower roots. They have shut down because they are constantly under water and now your plant can't get the nutrients it needs.

 

[ReefKief]

I water her once every 4-5 days when the top layer of the soil is dry again. I'll try to water her less often then. I have been lifting up the pot to guess how much water is in the soil, but I guess I'm still too unexperienced to guess it right.
Do you think the plant can still recover? Thanks for the advice Emilya!

 

[Emilya Green]

I water her once every 4-5 days when the top layer of the soil is dry again. I'll try to water her less often then. I have been lifting up the pot to guess how much water is in the soil, but I guess I'm still too unexperienced to guess it right.
Do you think the plant can still recover? Thanks for the advice Emilya!

Yes, I think the plant can recover. All you need to do is stop paying any attention at all to the top layer of soil... it is totally unimportant that it gets dry up there. You need it to be dry at the very bottom of the cup when you water the next time. It might take a week or 10 days as damaged as your roots are. Please read my work on how to water so you can get a concept of the wet/dry cycle. The time between waterings with a healthy plant goes down dramatically each time you water... at first it takes 5-7 days to drain a container... then it will take 3, 2 and finally your roots are so strong that the plant can drain the container in one day, and then it is time to uppot and start this process again.