I was searching around the internet and found that metal halide bulbs are the best for recreating natural sunlight, which is not only good for plants, but animals as well. I recently bought some Java moss, Java Ferns and amazon swords for my tank. It gives my tank a whole new look which I really like. i was wondering what kind of light fixture I would need, i Just have a fluorescent atm. 4'. I was confused by the wattage in relation to the "k"? wondering if you guys could give me any info, thanks a ton
metal halide lighting
- Thread starter dcp5082
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You don't need high power MH, check out fishneedit.com, they have 70W MH light. I have one with 8000K color temperature and it looks great.
You might need to hang them a good distance above your tank depends on the height of your tank other wise you might have too much light and could have algae issue with the low light plants you have.
You might need to hang them a good distance above your tank depends on the height of your tank other wise you might have too much light and could have algae issue with the low light plants you have.
awesome site, thanks jp. will it fit in my current 4 foot flourescent light fixture? or will I have to buy an additional fixture to put the light in?
you don't need additional fixture, it comes with mounting legs and hanging kit.
I'm using only one over my 180g tank with it about 3ft above the tank. with just one the down side is the top brace of my 180g create some shadow area.
if you want to avoid that then get two with one on each side. unless you have a rimless or the brace is transparent.
I'm using only one over my 180g tank with it about 3ft above the tank. with just one the down side is the top brace of my 180g create some shadow area.
if you want to avoid that then get two with one on each side. unless you have a rimless or the brace is transparent.
dcp5082;4819700; said:
Wattage is a measurement formula for the brightness, intensity, and heat produced by an electric bulb in comparisson to candlelight. 100 watts is hotter, brighter, and more intense than 30 watts. Light degrades with water depth - a 30 watt bulb will make the bottom of a 12" deep tank brighter than it would a 36" deep tank. If you want to brighten up the bottom of the 36" deep tank increase the wattage.
Kelvin (K) when used for lightining is basically putting a tempature to the colors present when exposed by light. Zero Kelvin is black and produces no radiation. 5,500 K is a full spectrum of visable color, it's pretty much sunlight at high noon. Because light degrades with depth a higher k light source may be needed to get the full spectrum to the bottom of the tank.
In relation to plants the higher the kelvin the more UV light radiation is produced. The Kelvin scale goes full circle. UV - a,b,c are invisible on the opposite side of zero. Plants need differing amounts of UV lighting inorder to Photosynthize. Because lite degrades deeper planted tanks might require higher kelvin ratings depending on the species of plant. UV light does not penetrate glass so there needs to be a large enough opening at the top of the tank for the UV to penetrate. Not all plants need added UV. 5,000K typically produces enuff UV for plants.
Kelvin is also a controlable personal preference when it comes to fish depending on how much and which colors you want to see more pronounced. Looking at 5,500k as a Nuetral starting point making green as the pronounced color, to make the yellows and reds more pronounced lower the kelvin to make the blues and purples more intense raise the kelvin.
Otherone;4820787; said:
I am going to disagree with you on the grounds that most if not everything in this post in innacurate. UV has nothing to do with colour tempurature in flourescent and metal halide bulbs. In thermodynamics as you increase the tempurature of an object the light will get progressively bluer. For example 1000k is red, 5000 is white, 10000k is blue-white. Flourescents don't work by the laws of thermodynamics so they don't have an actual colour temp but instead are given a vague comparison to an actual black body radiator at a given tempurature. A comparison of only the colour, mind you not of the actual spectra emitted. Yes a black body radiator at 5000k will produce more UV than one at 3000k but a flourescent with a CCT(corelated colour temp.) of 5000k will produce roughly the same UV as one with a CCT of 3000k. The amount of UV emitted by flourescent lamps is negligible 8 hours under a flourescent lamp is equivalent to 8 minutes in actual sunlight in terms of UV output.
Plants do not require ANY UV radiation to grow. UV is infact harmful to plants (just as it is harmful to animals) Plants use the red and blue portions of the spectrum to photosynthesize. If higher kelvin tempurature lamps produced more UV then saltwater aquariums would be barren, lifeless, tanks becuase of how high the colour temp is on some of them.
If plants needed UV to grow all mine would be dead because i have them growing under a glass lid which filters out 99.9% of all UV.
Nor is wattage a measure of how much hotter or brighter a lamp is in comparsion to candlelight
. Wattage is a measure of power consumed. An incandescent lamp at 100 watts will be much hotter but less bright than a flourescent lamp at 100 watts. Higher colour temps are not needed on deeper tanks because as the light goes deeper it's the reds and the yellows that are lost first. If anything you'd want more red's and yellows to compensate. Regardless, the depth of water in most tanks isn't nearly deep enough to see any blueshifting of light. All you really have to worry about is the intensity. You'll need alot more light in a 36" deep tank than you would in a 24" deep tank.
i really don't think you need metal halides on this tank. A single T5HO bulb spanning the length of your tank will be plenty. All your plants would qualify as low-light and a metal halide unless it is hanged waaaay above your tank would give you serious algae problems.
i have to agree on t5 as well. in addition to the potential for excessive algae growth, you also run the potential for severe increase in tank temps. mh lights run very hot...on a 90g a t5 fixture should be plenty to grow most any plants you select for f/w.
T5HO is the way to go. All the plants you have require little light anyhow. Save the money on the light setup and electricity and get a T5HO lamp.