# [Wet Thumb Forum]-6500K or 10000K Aqualight for freshwater plants



## Tom E. (Feb 6, 2003)

Greetings,

I am looking to replace my flourescent strip with a more robust lighting solution. I have pretty much decided to get the Aqualight 36" fixture, but would like a few questions answered.

1) Many of the posts regarding the Aqualight on this board indicate that I should use a 6500K light rather than a 10000K light. Is the 10000K light designed to meet the needs of corals rather than FW plants? Would a 10000K light "burn" my plants or bother my fish?

2) The most recent line of aqualights released come equiped with a 10000K bulb, and Actinic bulb, and the mini Lunar LEDs. Is there any advantage in getting this if I do not have a reef tank? 

2A) Is there any benefit in simulating lunar light in a FW tank with plants and fish?

2B) Are there any advantages to actinic lighting in a FW tank?

3) If I have the aqualight directly on top of a glass canopy, will I lose a significant amount of light intensity due to reflection from the glass?

Thanks much,

Tom E.


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## imported_BSS (Apr 14, 2004)

Here's my take:
1) The 10000K will not harm the plants nor fish. Some would state that the light spectrum isn't optimal for FW plants. IMO, so long as you are in the 5000K to 10000K range, the bulb should be just fine, as long as you like it.

2) Everything I have read states that an Actinic buld is zero value add for FW plants. It is designed specifically for corals. So, I can't recommend the Actinic part. As to the moonlights, they seem pretty cool. They will allow you to get a glimpse of nocturnal inhabitants, and somewhere I read it seems more natural for the fish to have a "moon". (But is it a moon if it is more than one light? Should it change position? These are the types of things I think about







).

3) So long as you keep the glass good and clean, there should be no significant loss. However, it can lead to heat issues within the tank. Mine didn't when I was at 2x55w. But, as soon as I got a 96w (which I really like!), heat absorbed by the glass and radiated into the tank became a problem.

Good luck,
Brian.


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## imported_russell (Sep 14, 2004)

1. agree with bss, but if you have the extra money go ahead and get the 6500, 6700, or 9325.

2. agree with bss

3. just make sure your glass doesn't get so hot that is cracks and falls in the tank. it happened to me


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## bharada (Apr 17, 2004)

I have six 1x96W Aqualights, 2 over my 40g tank and 4 over my 125. The new fixtures you're referring to are aimed toward SW use so there's no bulb choice except for the 10000K+Actinic.

My favorite bulb is an 8800K which is a nice clean white with just a hint of pink to soften it a bit. I use a pair of these over my 40g tank.

A 10000K bulb is very, very bright white that can wash out colors. Over my 125g tank I have a pair of these combined with a pair of 8800K bulbs. While these bulbs are very crisp over my 40, over the 125, either due to the added height or the thicker glass, the light is more subdued.

Lunar lights provides a cool way to see your fish when the main lights go off, but it's more a novelty in FW as opposed to being a breeding enhancer for corals and such in SW.

Directly on the glass top, a 96w strip will increase your tank temp a good 3-4°. Light intensity should be fine. I have all my light fixtures on legs to keep them about 3" off the tank.


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## TWood (Dec 9, 2004)

> Originally posted by BSS:
> 2) Everything I have read states that an Actinic buld is zero value add for FW plants.


Read this then:

http://www.marineland.com/reports/3Lighting.asp

"Plant tanks require the correct lighting to be successful. The number one reason for lack of success in growing plants in an aquarium has to be the use of the wrong lamp. Plants have two types of chlorophyll; a and b. Chlorophyll a absorbs light at 405 and 640 nm. Chlorophyll b has a peak absorption at 440 and 620 nm. Plant lamps are designed to emit light at the red wavelengths to duplicate the job of the sun. But too much red color can cause aquatic plants to grow tall and thin. For best results, use a daylight (5,000 °K) lamp such as an Aquasun, Ultralume 50 or Chroma 50 in combination with an actinic white or actinic day lamp. The actinic day or white lamp is a mixture of 50% actinic (blue light) and 50% daylight. In large or deep aquaria consider using HO or VHO lamps."

And:

"Wavelength is another terms that is important to understand especially in the context of lamp descriptions such as full spectrum or peak wavelength. These terms refer to the wavelength output of the lamp or bulb. Actinic lights, for example, produce only light at a specific wavelength - 420 nm. This peak wavelength value, which produces a very blue light, was chosen because during photosynthesis chlorophyll a absorbs light near this wavelength. To promote photosynthesis in reef coral actinic lamps are used. Some lamps have two, or even three, peak wavelengths."

Then look at the spectrum charts here:
http://www.championlighting.com/e/e...ng/pclamps.html

The only way actinic lamps would have "zero value" for plants is if plants had no type a chlorophyll, something that is not true. I've seen plant tanks with a portion of the lighting being actinic, and it's an interesting look. Darker to the eye, but still grows plants.

TW


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## imported_BSS (Apr 14, 2004)

TW - thanks for the correction. In the future, I'll avoid the use of 'zero value'? Would you recommend someone purchase actinic for a planted tank?


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## TWood (Dec 9, 2004)

> Originally posted by BSS:
> Would you recommend someone purchase actinic for a planted tank?


If it provided the 'look' they wanted, yes, but only as part of the lighting. I'll be switching my two 96W PC lamps to a 50/50 actinic/10,000K coupled with an 8800K the next time I relamp. Since each lamp is two tubes, that will make one of the tubes actinic and the other three daylight. I'm hoping it will make the tank look darker while still providing enough PAR.

TW


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