algae growth under led vs. mh

[Growenhaft]

Algae should actually grow particularly well when there is a high proportion of blue light... in aquaristics this is presented as a fact.

I currently have the same cuttings under 600w mh with extreme blue light and 660w led fluence spyder 2p...


rock wool under mh

rock wool under led

one would like to assume it should be the other way around... does led have so much more usable blue light than an mh specially developed for blue light?

Edit 400w mh not 600w sry

 

[Creeperpark]

Good observation. You can cover the Rockwool with white plastic or cardboard to keep the green out as you already know. Thanks for sharing that information. Very helpful.

 

[stiff]

That green never does any bad to me...I couldn't be bothered doing more than raising the airflow around it. That does the trick too
But it looks like you got a sunburn there..I'd dim them down a notch or raise the light. I guess its an old burn and u dealt with it already

 

[Growenhaft]

thank you for your answers..

I don't really like the algae... although they are not a problem for the plant itself... but they attract mourning mosquitoes and mold... therefore better no algae in the rock wool.

so far, however, I have never had to do anything about algae... the combination of mh for growing and natruim steam lamp for flowering had always worked well that only low algae growth was noticeable. Actually, I expected by switching to led that the algae growth will be even less... but never again!

I will take 2 better pictures later when my light is turned on... where you can see the difference even more extreme... because if only one were affected, this algae growth could be due to other circumstances such as light... but that's not the case... they are all under led in moss green stone wool cubes... and all under mh in yellow with only slight algae growth.

for me it's just a matter of understanding what could be the reason... all cuttings were treated equally... all the same variety the same water the same cubes... the only difference is the light source. and every theory says that this should not be so.

 

[stiff]

I can only say its not happening for me with the bigger size eazy plugs, but I never tried rockwool.
On your pics it doesn't look like it would affect the coco. Maybe just get rid of rockwool at all?

 

[Cloneman]

Good observation. You can cover the Rockwool with white plastic or cardboard to keep the green out as you already know. Thanks for sharing that information. Very helpful.

Like he said, I made white plastic covers for mine. No more algae

 

[Growenhaft]

Maybe just get rid of rockwool at all?

Rockwool cubes offer an incredible benefit when used properly. easyplug are really good for everyone... but if you want rapid root development, nothing beats rockwool half buried in coco. the roots grow very quickly through the rockwool... but then very quickly touch the foil... which in turn stimulates root division... as the pot progresses, the roots will be much stronger and more evenly rooted than if it were only a small one wedge rock wool without foil or easyplug.

to get the same results there you would have to repot... work with small pots which allow pruning of the roots by light and air... that takes more time. but that's not really the point here...

everything is the same... some under mh specially developed for blue light with 400w instead of 600w as incorrectly stated in the first post... the others under fluence spyder 2i.

the light diagram of the 400w mh

it should be the other way around... it should be less under led than under this mh... but never more... i don't understand.

 

[stiff]

I have to admit.. my mars ts1000 performs better for cuttings and seedlings than my sp6500 dimmed. And also the ts3000 makes them grow much nicer in veg than the big gun. I guess its about colour spectrum or so.
Thanks for the explanation about the rockwool cubes, I'll check it out,since someone gave me a few

 

[JKD]

Perhaps MH emits enough UV to control the algae.

 

[Growenhaft]

according to the light wave diagram of the mh... see the picture in the post above... no... hardly any uv... certainly significantly less than the led with extra uv light led... it's completely paradoxical

 

[JKD]

Unless the lighting diagrams are indictative only, rather than accurate.

It would be great to measure both if you have the equipment, or have a comparison plant in sunlight.

Or even just a rockwool cube kept 'fertilised' and damp in the sunlight to see if algae forms.

 

[Growenhaft]

such a massive deviation? I think that's out of the question... especially since the uv light component of the led is specified as being very high... so this would have to have an extreme downward deviation... otherwise this wouldn't be possible.

Maybe blue light is refracted differently underwater... so more blue light algae grows underwater... because the water changes the spectrum... and that spectrum is better served by the LED in non-underwater conditions? paradox

 

[JKD]

Perhaps this? From an aquarist site: "The Metal Halide Lamp-150w 14000k keeps very little yellow light in its colour spectrum and this will help to keep algae down in the aquarium."


Or perhaps it's the combination of blue & red in the LED.

"So what to consider when choosing lights for algae growth?

• White – sunlight has a broad spectrum, so white light can work for all species. Note that different “white” light sources may have different spectra, and few replicate the broad output of natural sunlight.
• Red and blue – these colours are strongly absorbed by all microalgae and tend to yield the fastest growth rates for most species.
• Other colours – may be absorbed well or poorly depending on the species. Can be very important for specific applications e.g. production of specific pigments."

Microalgae Growth Light Spectrum - Industrial Plankton

Not all light is created equal. Microalgae Growth Light Spectrum can have an impact on how algae grows and photosynthesizes.

industrialplankton.com

 

[Growenhaft]

the thread can be closed... everything is as it should be. if something speaks against all scientific theories... it is inexplicable.. the error is usually in the detail... and mostly on the part of the user and not the science.

in this case it was the wrong lamps in the wrong packaging. I guess there was a mishap while cleaning up the last time around... the packaging didn't contain 400w mh with blue light... but actually 600w mh with a very high proportion of red and uv light... 5600 kelvin... which is actually ripening the buds is... with extra little blue light... fuck.

for 4 days i've been rather dissatisfied with the thickness of the trunks... the distances between the nodes are also longer than usual at this very early point in time... something wasn't right for me...
So today, after racking my brains for a long time, I decided to replace the illuminant with a 600w sodium vapor lamp. then i took a close look at the bulb... whether it was used up... or damaged... everything seemed to be fine... i then saw the imprint more out of the corner of my eye... 600w mh... the i I also operated it with only 400w...

it's no wonder that the algae didn't like it. nevertheless.. the growth of algae under the fluence is already enormous... but it's positive to see... not only the algae need it to thrive... the plants too... and so the cubes don't get any direct light anymore.