Aquarium Light Tubes

[Tropical_Fish]

The tank I got didn't come with a tube for the light, but it did come with the starter and light fittings.

The starter says to use 18-20w bulbs

From measuring the clips. I need a 24" bulb.

I was looking at the AQUAR range of tubes. I have the choice of three.

AQUARGLOW 24" 18 Watt
AQUARDAYLIGHT 24" 18 Watt
AQUARMOONLIGHT 24" 18 Watt


It's for a tropical tank

 

[drobbyb]

The differences in the bulbs are the color of the light known as K rating. The Aquaglow is a nice color bulb for showcasing colors. The daylight and moonlight bulbs simulate natural light.

As to which is better, it's all up to your personal preference.

 

[OldMan47]

If you are growing plants, get a bulb with a K rating of 5500 to 6700K. Real noon sunlight near sea level is about a 5700K spectrum. That will simulate daylight at noon fairly well and work with plants. If you are not growing plants, think about the colors that you like instead. A warm white bulb with a color rating in the mid 2000K range is rather yellow to the eye, a 6500K is a bright color that casts strong shadows in your tank and a 10000K light is a harsh bluish white color like you might see in a salt water display tank at the LFS. All of the lights are much the same when it comes to fish health, they don't affect it much, but the perception to a viewer is quite different and very personal. The "plant lights" tend to be a pinkish looking light that may have a very slight advantage for growing plants but are terrible, in my own opinion, to look at. It is really up to you and what you like.

 

[waterdrop]

If you are growing plants, get a bulb with a K rating of 5500 to 6700K. Real noon sunlight near sea level is about a 5700K spectrum. That will simulate daylight at noon fairly well and work with plants. If you are not growing plants, think about the colors that you like instead. A warm white bulb with a color rating in the mid 2000K range is rather yellow to the eye, a 6500K is a bright color that casts strong shadows in your tank and a 10000K light is a harsh bluish white color like you might see in a salt water display tank at the LFS. All of the lights are much the same when it comes to fish health, they don't affect it much, but the perception to a viewer is quite different and very personal. The "plant lights" tend to be a pinkish looking light that may have a very slight advantage for growing plants but are terrible, in my own opinion, to look at. It is really up to you and what you like.

Gosh! Just a really great paragraph there OM47! Personally, my own "personal cheatsheet" of where "spectrum" fits into ones skillset about light in a planted tank remains not fully formed and rife with confilicting bits of information. On the whole I feel I've read rather a lot of posts and other paragraphs that more or less remove spectrum as a big issue for the actual growing of plants (eg. debunk any thought that "plant lights" or such will "grow them better.") and yet one of the areas where the topic of spectrum remains controversial, at least to me, is that of algal growth and the photoreduction of iron.

This topic is covered on pp. 167-170 in Diana Walstad's "Ecology of the Planted Aquarium" and I should probably not attempt to condense the practical take-away message as I've not re-read it in detail lately but the thought I'm remembering was the potential for light below 500nm, in the blue and ultraviolet range, to have enough energy to break the chemical bonds used by dissolved organc carbon molecules in our tank water to chelate iron, thus freeing up iron that algae could readily use as an extra source for rapid growth. The Rich & Morel experiment comparing normal light with light where the blue/uv light was filtered out is I believe where the interesting graph came from that she shows.

In the long run this may not turn out to really be a big deal for algae, but its one of the areas that I still feel is interesting!

~~waterdrop~~

 

[OldMan47]

Very high energy photons may well be capable of breaking chemical bonds. Actually I would be surprised if that is not the basis for a UV sterilizer. I just re-read that section of the book and she is definitely implicating the blue end of the spectrum in breaking chemical bonds that would otherwise make iron unavailable to algae. She specifically cites a strategy that she used to combat a bad outbreak of green water where she removed the "plant light" and left only some natural daylight and a warm white bulb in order to shift the spectrum to one more likely to favor plants over algae.