It was doing great

[SmokingWings]

f course, my reason for making the post to start with was to discover the reason for the blackened leaf tips and the suddenly stunted growth. I certainly don't want to repeat this.

From msg #18:
Everyone seems so concerned about my use of hydroton. We've been using hydroton for years. Is it really so bad? I've grown in hydroton before and it has never caused my seedlings to stop growing and turn black.
............
Do you guys really think that the blackening of the leaf tips is because of the hydroton? I'm leaning towards a nute burn or nitrogen toxicity. Remember, they were growing well, in the hydroton, until I added 1/4 strength nutes.

I have a suggestion about the spots that you can consider and here is how I came up with it. Almost get the feeling that we were all looking at the problem but did not follow through with what we were seeing. Here is my theory on what the problem is, what caused it, and what to do about it.

I get the feeling that the concern about the hydroton is just because it is not as common of a growing medium as typical dirt/soil or a peat moss or coco coir mixture. You have become used to using it but I figure that most of us are still adapting or getting used to what we are looking at in your photo.

In the first picture we are seeing drop of water on the side of the cup. The surfaces of the hydroton balls are glistening from all the water. If the photo was of a seedling in a cup of soil and that soil was glistening most would have keyed in on too much water right away like we did for the clay balls.

The spots on the leaves have nothing to do with fertilizer or with Nitrogen or with toxicity. Not an issue of too much of any nutrient nor not enough. It is all in too much water on the surface of the immediate area and the use of a plastic 'dome' so as to trap even more water vapor, maybe as a way to promote root growth or maybe something else. But, the dome is contributing to the problem.

The clues are the black spots on the leaves and what looks like the same sort of spots on the hydroton. We were seeing the problem but it was a case of "can't see the forest because of all the trees".

I figure you have one of the most common problems that effects plants all over the world. I figure we are looking at a case of "Black Spot Mold". If we were looking at Maple trees we could call it Fire Blight or if at Roses we could call it simple "Black Spot".

You could panic and toss it or you can make a few changes to make the problem go away and save the seedling. Toss the dome, do not mist the plant or the cup or the hydroton. Just pour what is necessary over the clay balls for the roots. Let it dry out as much as possible but maintain moisture just for the roots. The leaves or any part of the plant above the hydroton line does not need all that water.

When the leaf surface and the hydroton dries out it should be enough to kill off the black spot mold, preventing it from throwing spores and keeping the surface moisture under control should keep it from coming back.

It is what I have done a time or two when I had the same sort of thing show up very early in a seedling stage or when trying to get cuttings to start rooting. Letting the surfaces get dry and the plant recover in the next 7 to 10 days might be all that is needed. If it was me I would wait it out. If after the week to 10 days it was still an issue then I would consider tossing it, doing a bit of sterilizing and trying again.

 

[013]

great job Smoking Wings!

 

[FishFlavouredTimbit]

I figure you have one of the most common problems that effects plants all over the world. I figure we are looking at a case of "Black Spot Mold". If we were looking at Maple trees we could call it Fire Blight or if at Roses we could call it simple "Black Spot".

It isn't mold. The hydroton is cracked. The black part is the inside of the clay balls. The brown outer coating is just cracked off in some places. It is "Growit" brand hydroton. Every pebble is exactly the opposite of a 'ball'. Not one of them is round.

You could panic and toss it or you can make a few changes to make the problem go away and save the seedling. Toss the dome, do not mist the plant or the cup or the hydroton. Just pour what is necessary over the clay balls for the roots. Let it dry out as much as possible but maintain moisture just for the roots. The leaves or any part of the plant above the hydroton line does not need all that water.

Good advice. That is pretty much what I have been doing for 2 days now, and it has been working. There are two new leaves emerging. I am switching to just spraying the surface of the hydroton every few hours just to keep the rest of the HT moist.

Letting the surfaces get dry and the plant recover in the next 7 to 10 days might be all that is needed. If it was me I would wait it out. If after the week to 10 days it was still an issue then I would consider tossing it, doing a bit of sterilizing and trying again.

The good news is, there are definitely two new leaves emerging. I am spraying the HT surface every 8-ish hours just to keep it damp. I am using spring water pH'd to 5.6. I promise you, there is no stagnant water at the bottom of the container. The drain holes are clear. As you suggest, I am going to give it more time to recover.

The water glistening on the surface is because I had just sprayed it to moisten it again. Honestly, I don't keep it wet. With 17% RH, I have to spray the hydroton every few hours. I've been flushing every 8 hours just to help flush the excess nutes. I don't think I need to do that anymore. I'm just going to lightly spray the HT from now on.

I have to say, I am very surprised that the nutes I added were excessive. I have seen people in this forum talk about 1/2 strength nutes from day #1 with no issues. I suppose it might be a trait of each individual strain. Some are more delicate than others. This is my first time growing Black Gorilla from Crop King Seeds.

When I grow the rest of those seeds, I will be much more careful.

I am waiting for delivery of my new pH tester. I am finished with $18 pieces of crapola. It is impossible to accurately test the pH of distilled water with an electronic tester unless some electrolytes are added. Even then, the $18 units are too unstable I've owned three so far. They are all of similar quality. My marijuana deserves the very best I can afford, right? So, I opted for an Apera Instruments PH60 ($135). Since I use distilled water when I 'build' my nutrient water, it is vital that I can accurately measure pH.

When this problem first appeared, I did wonder if it might be a pH problem causing a lockout. I never really trusted my pH meter.

Thanks for your help. I appreciate it.

 

[SmokingWings]

It is "Growit" brand hydroton. Every pebble is exactly the opposite of a 'ball'. Not one of them is round.

I have come across them referred to as 'balls' of clay no matter what shape they are which is why I used the word.

The hydroton is cracked. The black part is the inside of the clay balls. The brown outer coating is just cracked off in some places.

Yep. I had run into that before with the stuff and forgot about it. Them pesky little black spots where the brown surface breaks off.

 

[Delps8]

Everyone seems so concerned about my use of hydroton. We've been using hydroton for years. Is it really so bad? I've grown in hydroton before and it has never caused my seedlings to stop growing and turn black.

Do you guys really think that the blackening of the leaf tips is because of the hydroton? I'm leaning towards a nute burn or nitrogen toxicity. Remember, they were growing well, in the hydroton, until I added 1/4 strength nutes.

I'm still in disbelief that such a small amount of nutes can cause all this carnage.


Humidity is 17%. Dome removed. I'll watch it carefully to ensure it doesn't start wilting. Thanks.

No. Hydration is inert.

I haven't looked closely at this thread but it's not hydroton causing the issue. Hydroton is just expensive, porous rocks. I grow in hydro and use RapidRooters first, then into net pots + hydroton.

Growers need seedlings to need nutrients but the seedlings don't. Seedlings generate glucose from photosynthesis and the tiny amounts of nutrients they need are found in the cotyledons. I can't cite the source but I've read "somewhere" that cannabis plants don't need nutrients until they grow their first set of true leaves.

Re adding CalMag and pH'ing water - I used to do this "because". No more. The main reason to pH the res is for nutrient uptake. Since seedlings don't need nutrients until they grow their first set of true leaves, I don't understand why we do this. I use tap water and haven't had any issues.

 

[FishFlavouredTimbit]

I haven't looked closely at this thread but it's not hydroton causing the issue. Hydroton is just expensive, porous rocks. I grow in hydro and use RapidRooters first, then into net pots + hydroton.

I might give rapidrooters a try. So many of you use them, you can't all be wrong. Right?

Re adding CalMag and pH'ing water - I used to do this "because". No more. The main reason to pH the res is for nutrient uptake. Since seedlings don't need nutrients until they grow their first set of true leaves, I don't understand why we do this. I use tap water and haven't had any issues.

If I had more experience, I might be a bit more free wheelin'. As it is, I'm just trying my best to do it right. I don't want to skip any steps yet. After a few more grows, perhaps. Until them, I'm gonna take 2 minutes to pH the water.

Just to clarify - the first true leaves are the first ones after the cotyledons. Right?

 

[SmokingWings]

Just to clarify - the first true leaves are the first ones after the cotyledons. Right?

Yep. The first leaves that will have the same characteristics as the leaves found on a more mature plant. In the case of the Cannabis plant the first true leaves have the long slender shape with the serrated edges. Usually they have only the single finger or blade but sometimes will show very small fingers on either side right at the base where the leaf stem starts. The next set of leaves will have 3 fingers.

 

[FishFlavouredTimbit]

SmokingWings: I love this site. I learn something new every day. Thanks!

So, here's some good news. My new pH tester arrived today. I calibrated it right away, and tested the water I was feeding my little seedlings. It was 4.2! I thought it was 5.6. My Vivosun pH pen (I was never very confident in its accuracy) showed 5.6. Anyway, I corrected the pH and flushed everything with pH5.6 spring water. There are two new leaves emerging, but the first two leaves are very twisted and weirdly shaped. It is still struggling to survive. It has been 13 days since I germinated the seed. The cotyledons are brown and crispy. There is no more energy there to give. I think it is time to add some nutes. I will go with Revive at a strength of 0.5ml/L - about 1/6 the normal strength.

I will give it a few more days to show improvement. At that point, I will need to either transfer it to my DWC setup, or start again with new seed. It is improving, but not vigorously. By this point, I should be looking at three sets of leaves. I'm hopeful, but not overly optimistic.

 

[Delps8]

I might give rapidrooters a try. So many of you use them, you can't all be wrong. Right?

If I had more experience, I might be a bit more free wheelin'. As it is, I'm just trying my best to do it right. I don't want to skip any steps yet. After a few more grows, perhaps. Until them, I'm gonna take 2 minutes to pH the water.

Just to clarify - the first true leaves are the first ones after the cotyledons. Right?

Yup, the first "serrated" leaves.

 

[FishFlavouredTimbit]

I grow in hydro and use RapidRooters first, then into net pots + hydroton.

I ordered 50 RapidRooters. I'm looking forward to giving them a try. If it makes the seedling/rooting phase easier, I'm in!

 

[Keffka]

Growers need seedlings to need nutrients but the seedlings don't. Seedlings generate glucose from photosynthesis and the tiny amounts of nutrients they need are found in the cotyledons. I can't cite the source but I've read "somewhere" that cannabis plants don't need nutrients until they grow their first set of true leaves

Glad I double checked because I saw OP mention twice about other growers saying nutrients from day 1 and I was gonna mention it. Those growers are very wrong.

Cannabis can usually go about 10-14 days from the time it comes above ground before it will need the growers input. Source: True Living Organics by The Rev and also Teaming with Nutrients by Jeff Lowenfels. This is important knowledge for organic growers since they need to get myco established (which needs low available nutrients to properly colonize) and the medium prepped (microbes populating to make nutrients available) before then.

As a synthetic grower when you give nutrients your plant begins taking them almost right away, so it’s important you hold off in the very beginning. Good luck OP!

 

[FishFlavouredTimbit]

I've had the seedlings in a rapid rooter for a few days. No change yet. It's been 9 days since they germinated.

If you remember, I had two other seedlings in hydroton before the two seedlings I currently have, but they did very badly and seemed stunted. I gave up on them for my hydro grow, but I replanted them in soil to attempt a revival. Well, here they are today.

Both plants have split into two growth nodes. They also have these weird leaves that look nothing like cannabis. They look more like oak leaves. I am going to vegetate them until spring. I will plant them on the south side of my house after the last frost. They will already have 3 months of vegetative growth by the time I transplant them.

Thanks for all of your advice, everyone. I'm very grateful.

 

[Regrowth]

I get the shinny, sometimes rough or mutant looking leaves when I root clones in unamended peat.
I think it's something to do with the pH being low and nitrogen being more available than other stuff at low pH levels.
Not sure what soil you're using. They could just grow out of the weird phase but might be worth looking into if they dont.

 

[Azimuth]

Are you committed to the hydroton/dwc path? Sounds like you're having a bunch of issues whose source could be several different things.

As a new grower it might be easier to get a successful crop by going the more standard soil route. Much more forgiving if you make a mistake and at this point you don't really have the experience to know what you should be doing or how to correct things if the grow goes sideways.

If you are committed to dwc you should try to follow the journals of a few experienced growers doing just that. You'll pick up pointers along the way and be able to ask questions about their practices and yours.

 

[FishFlavouredTimbit]

I get the shinny, sometimes rough or mutant looking leaves when I root clones in unamended peat.
I think it's something to do with the pH being low and nitrogen being more available than other stuff at low pH levels.
Not sure what soil you're using. They could just grow out of the weird phase but might be worth looking into if they dont.

The pH was way off when I initially germinated the seeds. I got an Apera PH60 pH tester a few days after the leaves turned dark. The water tested at pH 4.2. They were severely stressed. I didn't think they would survive, but they did. They are now getting pH6.2.

 

[FishFlavouredTimbit]

Are you committed to the hydroton/dwc path?

Of course I am. My first hydro grow was in 2002.

Sounds like you're having a bunch of issues whose source could be several different things.

Any specific advice? Can you give me a hint as to which of the "several different things" it might be? The choices are:
nutes, pH, media, temps, genetics, RH, and/or lights.

As a new grower it might be easier to get a successful crop by going the more standard soil route.

Why do you, instead of helping with my specific problem, offer advice such as, "Change your entire hydro setup to a soil setup."? Do you really think that is helpful advice?

If you don't understand how DWC works, or you don't like it or use it, then you don't really have any advice to offer, do you? I've grown in soil and hydro before. I prefer hydro.

Much more forgiving if you make a mistake and at this point you don't really have the experience to know what you should be doing or how to correct things if the grow goes sideways.

You might be a really nice guy, but you come across as someone who really reckons himself. You seem to have a lot of advice that is basically:
1. I have a problem caused by possibly "several things". No specific advice, of course. Other than nutes, pH, grow media, temps, genetics, RH, and/or lights, what else COULD it be?
2. I should seek advice from others. (If only there was a website I could visit...)
3. I should switch to soil despite having a DWC setup that has worked flawlessly for over 4 years.

Sorry if I come across as abrasive. I am just frustrated with useless opinions being offered instead of useful advice. I come to this site to get advice from experienced growers. I kinda expect that someone will be able to answer the question I pose. What I see more often than not, is this:

me: I have a problem with water temps in my DWC
Rando: Are you growing is soil?
me: No, hydro.
Rando: There's your problem. Plants don't grow well in hydro. I have NEVER grown in hydro. I'm a soil guy with 3 grows under my belt. You can trust me. Switch to soil and you won't need to worry about water temps.

I have asked about how to get a germinated seed to root in hydroton, and the advice I got most often was, "Try growing in rockwool" Again, not answering the question asked.

 

[Azimuth]

Hi everyone. I'm a pretty new grower. I'm learning a lot from you guys, but I have many more things to learn...it's fun though!!!

You, yourself, posted that you were a new grower looking for help. As part of that process we usually ask various questions trying to get a better feel for your experience, problems encountered, general set-up, etc.

But, sounds like you have a real attitude and one I'm not willing to engage with, so I'm out.

 

[FishFlavouredTimbit]

You, yourself, posted that you were a new grower looking for help. As part of that process we usually ask various questions trying to get a better feel for your experience, problems encountered, general set-up, etc.

But, sounds like you have a real attitude and one I'm not willing to engage with, so I'm out.

So you have no advice then. Figures. Sorry you are so sensitive. Enjoy your day.

You're right, I did say that...I suppose I was trying not to be an arrogant know-it-all. I learn something every day on this site. I hope I never stop learning.

You didn't ask any questions about my hydro setup. Instead of helping with my problem, you immediately advised me to switch to soil. You probably think you're good at this. Weak. Take care.

 

[SmokingWings]

Any specific advice? Can you give me a hint as to which of the "several different things" it might be? The choices are:
nutes, pH, media, temps, genetics, RH, and/or lights.

Why do you, instead of helping with my specific problem, offer advice such as, "Change your entire hydro setup to a soil setup."? Do you really think that is helpful advice?

A big part of what is happening or happened is that most of us cannot get a hands-on experience to what the other person is doing. We are not there to touch and see the plant in person. We have to base our reply, growing suggestions, advice, and sometime praise, on what we see in photos or what we read in the other person's message. Sometimes it works and sometimes it doesn't. And when it does not work it can become frustrating for everyone.

The water tested at pH 4.2. They were severely stressed. I didn't think they would survive, but they did. They are now getting pH6.2.

I do not grow in hydro even though I find it fascinating. I see hydro methods as what will allow us, as humans, to get off this rock and start to build colonies on the moon or Mars or be able to mine the asteroids or try to get to other planets.

Anyway, I was under the impression that hydro methods worked best when the pH of the water being used, with or without nutrients, was at a pH of 5.8 and not a 6.2 pH. The 6.2pH is close to what is recommended for a soil grow.

 

[Delps8]

So you have no advice then. Figures. Sorry you are so sensitive. Enjoy your day.

You're right, I did say that...I suppose I was trying not to be an arrogant know-it-all. I learn something every day on this site. I hope I never stop learning.

You didn't ask any questions about my hydro setup. Instead of helping with my problem, you immediately advised me to switch to soil. You probably think you're good at this. Weak. Take care.

Just wondering - do you believe that your response was appropriate?