Dim light and Live Plants
When I do the water change and plant trimming on my 60 gallon Hex tank I have to remove the light fixture and hood. So I can see inside the tank I use a clamp on light fixture with a single incandesant daylight bulb. What I hve noticed during this maintenance is that my Glo Light Tetras look absolutely stunning. There color is much brighter and brillant than under the normal 6700k lights ( 3 18" tubes in the standard fixture) that are on the tank.
I now want to set up a tank with dim light and keep glow lights ( possibly Cardinal or Neons as well) in the tank but I will also want live plants as well. Besides Java Fern and Java Moss are there any other plants that would be sucessful in a dimly lit tank.
On a side note... Floating plants will not create the effect that this single bulb does. In the past I have had the foating plants get so over grown that the other plants were starting to suffer from the lack of light and the Glo lights still didn't look as good as they do under the dim light when doing tank maintenance.
I would gamble that it's not the volume of light making them glow- More than likely, it's the spectrum.
Try different combinations of current bulbs, full spectrum tubes, "warm white" tubes, and REVEAL bulbs (made by GE)
I bet you'll be able to find a balance thats bright enough for plants but still has the right bandwidths of light to make the fish glow.
Well, too bright of lights can wash out fish's colors, make them look pale.
The incandescent daylight bulb may be fairly similar in temperature to the 6700K you have in the T8's. Daylight CFLs are usually 6500K at least, I have never looked at incandescent.
Anubias are another low light plant that does will in dim light or shade.
Not much else though will do well in too low of light. Regular Amazon Swords might depending on how dim the light is.
Washed out colors happen because of stress,most of the time. I'd experiment with spectrums before you write off plants- an incandecsent light might be enough for anubias and java fern if you tie them on high points of your decor, but that's about it.
If so, the issue is likely too bright of lighting making them pale (likely stress) since it's possible the only difference between the two are intensity.
I know this is the case with Angelfish, under heavy cover they are much darker in color then if they go out into the open in the same tank, with the same lighting throughout.
if it is a true tungsten filament incandescent bulb it will be 2500K to 3500K max, for this type of lighting Kelvin is directly applicable in that the filament will actually reach that temp (and emit light of a corresponding spectral distribution)
some speculate that the irridescence exibited by glow lights and cardinals etc. serve the purpose of allowing the fish to be seen by others in dimly lit and tannin stained waters where they originated so if that is the case, it would make sense that the colors would stand out more in a dimly lit environment
There are a couple of factors at work here.
If you take some reflective multi-faceted object and hold it in very bright light, it tends to appear rather dull. But the same object in a narrower beam of less bright light can sparkle and shimmer as the light is reflected from the various surfaces. This is much the same with fish scales.
As you read through the fish profiles, you will see that many mention the fish species being more brightly coloured in dim light, often partly achieved by floating plants. This is partly due to the above, but also the fish is naturally more "relaxed" under less light. Bright light will usually cause fish to be stressed and their colours pale as a result.
My Congo Tetra always appear less colourful after I have thinned out the floating plants. As the plants increase during the week to eventually cover the entire surface, the fish become more brilliant.
Here is a short video of some fish in their natural surroundings. Even the most minimal aquarium lighting is brighter than this.
From what I have found out by researching the different bulbs from the 2 different fixtures the answer to the type of lighting I will need lies within the bulb/tube specs. This will also show that wattage is irrelevent.
Thetubes in the light fixture in use daily;
Quantity of 3 General Electric F15 T8/D tubes - The D = Daylight
Wattage - 15 watts per bulb X 3 = 45 watts
Daylight tone = 7500
Kelvin Rating = 6500K
Lumens, Initial = 700 X 3 = 2100 Lumens
Lumens, Mean = 615 X 3 = 1845 Lumens
CRI = 75
The Bulb in the fixture I use during tank maintenance
Quantity of 1 Sylvania Incandescent bulb
Watts = 100
Daylight Tone = unable to locate a spec
Kelvin Rating = Unable to locate a spec
Lumens = 1270
CRI = 100
Filiment = CC-8 - This a double coiled tungsten filiment burns at 4840 degrees with a kelvin rating of
2960K and does not include the coating on the inside of the bulb glass.
CRI is the Color Rendering Index.
Color rendering describes how a light source makes the color of an object appear to human eyes and how well subtle variations in color shades are revealed. The Color Rendering Index (CRI) is a scale from 0 to 100 percent indicating how accurate a "given" light source is at rendering color when compared to a "reference" light source.
The higher the CRI, the better the color rendering ability. Light sources with a CRI of 85 to 90 are considered good at color rendering. Light sources with a CRI of 90 or higher are excellent at color rendering and should be used for tasks requiring the most accurate color discrimination.
It is important to note that CRI is independent of color temperature. Examples: A 2700K ("warm") color temperature incandescent light source has a CRI of 100. One 5000K ("daylight") color temperature fluorescent light source has a CRI of 75 and another with the same color temperature has a CRI of 90.
With this information I have determined that I will have to find a light with a kelvin rating of 6500 - 6700 for the plants and for the fish the same light would have to have a CRI of 90 or better with a lumens output of 1270. If I understood all this data correcty and I can find a light with these kind of specifications I should be able to get the best of both worlds. A tank that will still grow plants and still show off the fish in there true colors.
I will post pictures of this tank under the two different light conditions to show you all what I am seeing when the tank light come back on for the day.
The biggest problem is that lumens and watts (when not comparing similiar bulbs) are useless when talking about plant lighting.
Quantum or Byron can explain why much better than me.
Regardless, I don't think it will give you the effect you are looking for. My thoughts are that the coloration of the fish under the incandescent bulbt is a combination of both quantity and quality of light produced, neither are ideal for plants. It may be the case where you can have one or the other (aquatic plants are not present in the natural habitats of most aquarium fish), but not both, though with some experimentation, you may be able to find a compromise.
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