Light color for anenomes...

[Ef3s]

sorry now on wii. i rread that a 10k bulb has more usable light than an ACTinic.

is this true

also is 185 watt compact flo at 14 inches depth enough light for a long tentacle ?

 

[metalac]

i thought it was the other way around since the blue light penetrates deeper.

 

[Ef3s]

anenomes come from shallow reefs not deep

 

[metalac]

anenomes come from shallow reefs not deep

oh i know, but i'm wondering how far do our lights penatrate? 5ft might be shallow for the sun, but our lights won't even approach that.

 

[Entacmaea]

185 watts should be OK for an anemone, granted you feed it regularly. Small whole shrimp/krill or fish are ideal, probably twice a week.

Regarding spectrum of your lights, it depends on what you mean by "usable"- if you mean which bulbs have the higher intensity wavelengths available for photosynthesis, then it would probably be the actinic bulb. But I'm sure it depends on manufacturer. Here is a good article to read to answer your question, title "Spectrum or Intensity" from Advanced Aquarist Magazine.

http://www.advancedaquarist.com/2002/2/aafeature

Best, Peter

 

[brandonberry]

To add to the lighting question, PAR value is the best measure of how useful a light is for photosynthesis. The same amount of photons at a shorter wavelength such as 420nm (actinic) is more concentrated than that of a higher wavelength such as 600nm. Often bluer bulbs have less overall PAR value though because even though they may put off more blue light than a 10k bulb, the overall amount of light across all spectrums is less. This is often the case with many halide bulbs as you will see if you read many of Sanjay Joshi's articles on spectral analysis. I have not seen any real comparison of compact flourescent bulbs, but I would suspect that it would be the same. I would love to see some of the spectral analyses of compact flourescent bulbs available in the hobby.

A simple comparison would be with change. While quarters are worth more than dimes, nickels, and pennies, 5 quarters is less money than 3 quarters, 5 dimes, 4 nickels and 8 pennies. The same is true when comparing various peaks at different wavelengths within the range of Photosynthetically Active Radiation (PAR).

When I choose lighting for my tank, I look for bulbs, or a combination of bulbs, that will produce some light across all visible wavelengths, but with a stronger concentration in the bluer areas to replicate the depth of water that my corals naturally occur. I also look for bulbs that can provide this while giving me the maximum amount of PPFD for the wattage bulb I have.

 

[ChrisRD]

As mentioned above, photons in the blue end of the spectrum contain more energy, but most of the photosynthetic animals we deal with in the hobby are exposed to a much wider spectrum of light (violet, blue, green & yellow) in their natural enivonments. Fortunately, they're very adaptable to various spectrums, so what particluar lamps you use isn't usually critical provided the animal gets enough PAR.

In general, the "daylight" type, wider spectrum lamps like 6.5Ks and 10Ks produce more overall PAR than bluer lamps, so 185 watts of 10K is usually going to get more useable light to your anemone than 185 watts of actinic. That said, wattage is a poor indicator of how much light the animal is getting as there are many factors here including reflectors, distance from lamps, type of lamp/ballast being used, etc.

Here's an interesting article where Sanjay compares some artificial light spectrums to natural sunlight at different depths:
http://www.advancedaquarist.com/2005/8/ ... hterm=None