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Humic Acid Buildup or Strong Light Burn?

Joined
Jan 7, 2004
Messages
439
Location
Utah
Hey everyone! Thanks for helping me out!

I have upgraded my amount of light and made sure the light was really close to my drosera with a slanted angle on the fixture to allow for taller growing plants and flowers on one side. For about four weeks now I have had this setup and been adding plants to my trays as I buy them online:

My setup
IMG_6844_zps5fa50uvf.jpg

IMG_6847_zpsydmfelml.jpg


As you can read on my hygrometer, just above the tray the Humidity levels are hanging around 31% and the TEMPS are 81 High with a nightly low around 66 degrees

Check out the images below and let me know what you think.

Are the conditions just too bright and the plants getting a little burned but will acclimate? I do have some leaves uncurling on the D. aliciae that has been affected the longest and so maybe things may be fine. (Recently fed there are several leaves furled right now) Or is this actually Humic Acid buildup from using the tray method and keeping the conditions constantly soggy? I have tried cleaning off the potential humic acid buildup with a q-tip but the leaves are stiff and the brown is dry or just doesn't come off. So I think burned a little. I should note that the plant affected for the LEAST amount of time arrived yesterday and is already showing signs of browning so I think it IS burning. One day is too short for humic acid buildup right?

What do you think?

The plants affected full plant and a close up. The pictures are ordered based on affected plant introduced to the lights the longest to most recent. The recent D. venusta has been under the lights for only 1 day.

D. aliciae
DroseraHumicMaybe-3_zpstdn8qf6x.jpg

DroseraHumicMaybe-4_zpsbz4ewjs6.jpg


D. sp 'Pretty Rosette'
DroseraHumicMaybe-5_zpsmvh4s07c.jpg

DroseraHumicMaybe-2_zpsp8plhrty.jpg

DroseraHumicMaybe-6_zpsme8f3d0b.jpg


D. venusta
DroseraHumicMaybe-7_zpsqh97we4s.jpg
 
Joined
Feb 22, 2014
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Location
Oregon
Yes that's humic acid. Light burn would result in existing leaves turning brown rather than blackening at the growth point.
 
Joined
Jan 7, 2004
Messages
439
Location
Utah
Yes that's humic acid. Light burn would result in existing leaves turning brown rather than blackening at the growth point.

Thanks, Nimbulan. It is harder than you would think to get Humic Acid buildup example images on the web. I just get inundated with Humic Acid additives for soil products.

I am curious why a single DAY of being potted up caused that D. venusta to be affected....that is mysteriously FAST for a "build up" of Humic Acid.

But per what I can see out there, I am lowering the water levels in the plants affected and will top water for awhile. Even though it will destroy my nice looking silica sand top dressing. :)

Any other advice for squashing this issue?
 
Joined
Jan 7, 2004
Messages
439
Location
Utah
A more thorough read of what Aaron wrote on GrowSundews.com pointed me BACK to Terraforums where Joseph explained the issue and the solution really well. In fact, Aaron quoted him almost word for word.

My plan to solve it is definitely going to be practiced, recorded and blogged about! I am excited to see the improvement!

Thread I am referring to: https://www.terraforums.com/forums/...iae-black-leaves-crown-5.html?highlight=water

Joseph's post:
<span style='color:red'>This is something that was reported on, I believe, back in the 1970's. Here is a short description of the issue.</span>

<span style='color:darkblue'>The darkening of the growth point, as shown by the photographs shared here, is caused by humic acids, and perhaps other solubles, wicking up and depositing themselves, first on the hairs and stipules of the leaf primordia, eventually covering the entire surface of the growth point and leaf primordia. My experience is that this can have a damaging effect on the growing point and can supress new growth. The easiest way to reduce this is to gently provide overhead watering with warm, purified water as often as necessary to reduce this precipitate. Another solution would be to use less peat moss, since it is a strong source for the most offending compounds, though other media ingredients may also be sources. It is also affected by temperature, ambient humidity, air movement, etc.</span>
 

nepenthesl0ve

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Dec 24, 2018
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a problem i wasn't even aware of existing until now, perhaps i should save it for when/if i ever go in a more drosera direction. hope they recover quickly
 

Not a Number

Hello, I must be going...
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Just flush the pots out from top watering without collecting the outflow water. Do it in a sink or just out a the lawn or garden. Do this a couple times a week until the plants stop drawing up the black residue.

The warm water treatment is very effective. Do this before flushing the pots.

The bale of peat moss I just bought seems to have humic acid in it. I just repotted my colony of D. aliciae and D. venusta. The D. aliciae started getting the build up.
 
Joined
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Messages
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Utah
a problem i wasn't even aware of existing until now, perhaps i should save it for when/if i ever go in a more drosera direction. hope they recover quickly
Yeah like Not a number said below, it is the peat. I am sure of it. I don't have the problem happening with any of my plants I didn't pot up myself except for the D. aliciae that had the problem first. That came with some humic acid yielding peat. Just take care when you buy your peat. Even thought mine says one ingredient...Peat. So I need to go read the fine print...maybe just maybe...

I have flushed the plant with warm water so far and will flush the pot more fully if needed. Looks really great so far! I am going to share some images here in a few mins!
 
Joined
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Utah
Check out the before and after images after an easy going warm washing of the growing points!

Using a turkey baster I have used SOLELY for watering CPs, I gave each plant a warm distilled water bath right at the growing point and then a gentle swabbing with a Q-Tip. Check out the tremendous improvement! Thank you to Nimbulan, Not a Number, Joseph Clemens and Aaron at GrowSundews for the help with their resources on solving this issue and fixing it.

I am very delighted with the results and will watch for wicking happening again and will flush the pot out even more if needed. Thanks all! :D

BeforeAfter_Comparison.jpg
 
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Joined
Feb 22, 2014
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Oregon
Just keep an eye on the problem to make sure it doesn't come back! I've found that the problem is sometimes periodic, coming and going seemingly at random. Some species don't seem too bothered by it while others get hit hard. Most of the time I end up repotting to solve the problem as it (at least for me) usually seems to be caused by bad peat.
 
Joined
Jan 7, 2004
Messages
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Utah
I wish all problems were as easy to resolve as this one! They look pristine once again :biggrin-new:

I know right!? haha thank goodness! I thought leaves were damaged and yet nothing is wrong at all except for the leaves I let GROW with the stuff on them. They are deformed a bit.
 
Joined
Jan 7, 2004
Messages
439
Location
Utah
Just keep an eye on the problem to make sure it doesn't come back! I've found that the problem is sometimes periodic, coming and going seemingly at random. Some species don't seem too bothered by it while others get hit hard. Most of the time I end up repotting to solve the problem as it (at least for me) usually seems to be caused by bad peat.

Yeah exactly my plan! I kind of expect this to come back at least once or twice. I am going to write up a blog post about the whole process so it is out there and I can share what you guys taught me and I learned from this. So I want to see how much if it all the issue comes back. Also, I am curious about my peat and I am going to go look over the entire bale and see if SOMEWHERE in small writing it mentions the "benefit" of humic acid in there. It's already hard enough to get Peat without Miracle Gro extras in it now I have to worry about the plain peat packages having Humic Acid? :nightmare:

Thanks again, Nimbulan for your help!
 
Joined
Feb 13, 2015
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It’s caused by evil spirits! See, baptizing cures!

Humic Acid results from the peat decomposing. One sundew, my creation, the fertile D. x obovata ‘Ivan’s Paddle’ is immune.
 
Joined
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Messages
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Utah
It’s caused by evil spirits! See, baptizing cures!
Hahahaha it is time these plants saw the light!

Humic Acid results from the peat decomposing. One sundew, my creation, the fertile D. x obovata ‘Ivan’s Paddle’ is immune.
Interesting...so it is safe to say that my Peat may NOT have extra humic acid in it but overtime developed it.

The process of rinsing your soil mediums before using it is something I half heartedly did but will be VERY intense about now. I would soak my medium and squeeze it out and then use it. After only one step of rinsing. From now on I will be doing the rinse and repeat recommended by Aaron here: http://www.growsundews.com/rinsing_peat_and_sand_for_carnivorous_plants.html

To keep on the religious theme, I am fully converted now to the process Aaron describes and will be doing it more seriously in my next potting. :D
 
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