# Is this the effect of blacklight fluorescent bulb or nutrients deficiency on my plant



## Amazonaquascaper (Sep 20, 2015)

Hi everyone
Im new here and i need help to understand what's happening at my aquarium plants i got 2 resun 20w 2 feet long 10000k each and 1 maxima 2 feet long blacklight 18w on my 90 gallons aquarium...i know you're thinking that this is too little light for an aquarium of this size but plant [seemed] to grow fine before these problems
I also got a sort of parasite outbreak before this problem and i dosed lot of salt thinking that it would killed the creatures and it worked!
Si my question is: Is it the blacklight that is deforming my plants or the lack of nutrients due to the large dose of Na+ affecting the absorption of other nutrients???
Thanks


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## Amazonaquascaper (Sep 20, 2015)

Does anyone knows something about it should i stop using the black light or if it's Na+ how to remove it


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## TropTrea (Jan 10, 2014)

you have a combination of two things here as you suspect.
Black lights are near UV lights with the output concentrated below 420nm. UV light especialy below 380nm starts to brealk down the cell walls of plants and bacteria. This is why it is used as a purifying phase to kill disease.

The saltt is something that many plants are sensative to. While there are some brackish plants like mangroves most aquarium plants do not like salt especialy in hoigh dosages. The only way to get rid of it is to do daily water changes of 30% to 50% for a wekk or even longer if the salt level was extreme.


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## Amazonaquascaper (Sep 20, 2015)

Does it means that blacklight is not good for my plants... I thought that short wavelength of light means more energy so more photosynthesis and also you said damage wall of living cell?? Blacklight doesnt it contain only uva and small percentage of uvb? I only know that uvc is used as sterilizers.
Uva forgot effect...
Uvb i think its for production of vitamin d3
Uvc sterilizer


So what do you think caused this deformation salt or blacklight they both happened at same time,blacklight introduced plant developed new leaves alternanthera reineckii developed new leaves!! even the light seem low
A Week later parasites started to kill some of my angelfish started dosing salt in small amount until required dosage was reached for my 90 gallon size aquarium,nothing happened so i added more salt then parasite died again a week later then symptoms started to appear on new leaves...
I'll try to get a pic of the plants tomorrow

Forgot to mention, fast formation of new leaves they seemed that they became dwarfs
I founded that the jungle vals' leaves became thinner larger at bottom and rapid change in width to become thinner at top
Amazon sword got leaves that curved to its side as well as pygmy chain sword
Java Moss and Xmas moss are growing new tips but thinner leaves they are rather growing horizontally than verticaly spreading on the branches 
Alternanthera r. Producing new red leaves with uneven leaf shape and holes as if it was breaking as if it was brittle


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## TropTrea (Jan 10, 2014)

with the black lights the light is concentrated well shorter than 420nm, which is the shortest wavelength that plants can utilize efficiently. Yes they can use some light as short as 380nm but that efficiency is near 0 at that level.

Black lights are designed to floresce pigments with an exciter current outside the range of the human eye. Most of there spectrum is invisible to the human eye and yes many produce UVA and UVB light with some also producing UVC. 

It is very debatable if UVA can harm plants? Some clain the water surface filters out enough of iut to make it safe. Other disagree. There is little debat about UVB being harmful as most experts say it is. And all experts firmly believe that UVC will actualy kill 99% of plants even at low levels.

Eye doctors have tied excessive exposure to black lights as a contributing cause to Cataracts. It is known that UV exposure is a known cause of Cararacts, so there is a tie here.

As far as the salt goes different plants have different tolerance levels for the salt.


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## Amazonaquascaper (Sep 20, 2015)

Plants deformation and the blacklight turned on and the way it is seen through my camera but with naked eye its a deep violet...and how it excites the white coloured fluorescent tubes


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## Diana K (Dec 20, 2007)

Bulbs with 10,000 K are already high in the blue end of the spectrum. 
I suspect you MIGHT be having a problem with little or no red wavelengths, and the salt. 

I think UV is not very effective going through the water. This is why a UV sterilizer sheets the water over the bulb, in thin enough layers that the organisms in the water get a proper dose to kill them. 

UV can also break down the chelators that are used in fertilizers. For example, the iron may be getting locked up faster than the plants can make use of it, if this is going on. 

The best way to remove the sodium (salt) from the water is with water changes. Most aquarium plants do not do well with salt.


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## Amazonaquascaper (Sep 20, 2015)

So if the blacklight has no high photosynthesis effect on my plants it means that only these 2 20w 10000k t8 bulb are growing my telanthera pretty well!! supposing their was no nutrient deficiency caused by the salt in my aquarium..
I've got a young telanthera shoot from a leaf!!!

Another 2 question: why the blacklight is seen pink purple through my phone camera and if my aquarium water was yellowish and i used the same type of 10000k bulb would there be too much blue wavelenght or does the aquarium yellowish water change it


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## Diana K (Dec 20, 2007)

The K rating on a bulb is the manufacturer's way of letting you know what the light will look like. It is the combined effect of whatever wavelengths the bulb produces. You need to research the bulb and see which wavelengths these are- are any of them in the red part of the spectrum that plants use? Probably little or none. Most of the wavelengths are in the blue end of the spectrum. This can make the red and orange fish and brown rocks or substrate look weird. Not enough red light is hitting them to make them look right. 

I do not know if the yellow tinted water actually changes a wavelength, or simply absorbs it. I think it simply absorbs it. 

If you cannot find the PAR rating for a bulb, most aquarium keepers use a bulb around 6,000K to 6,500K to try to get a more natural looking tank, and some each of the red and blue wavelengths that plants use. 

I usually set up 2 (or more) bulbs- one specifically aimed at plants, especially high in the red and blue parts of the spectrum that plants use, the other a 'cool white' or 'daylight' bulb geared to our eyes. To me this makes the tank look the most natural, and brings out the colors of all the fish. The cool white or daylight bulbs have some of the wavelengths that plants use, and the plant specific bulb has a higher PAR rating, so the plants grow well. 

I have no idea why the camera phone sees some of the wavelengths produced by the black light, or how the camera phone sees a black light. Obviously it can see something. It is interpreting whatever it sees it as a pinkish light.


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