10,000K Power Compact bulbs...

[Nospherith]

The need to upgrade my lighting is clear. My plants are basically not growing, and I'm really interested in establishing a respectable planted tank. I've read up on DIY CO2, substrates and plant nutritional requirements.

I found a light that seems right for my 24" 20g. I'm planning on getting this light. However, I've read that it is optimal for freshwater plants to have somewhere around 6,000K, but this light is basically 10,000K.

If I am correct, then K stands for Kelvin which is actually a measurement of temperature (relative to absolute cold, where atomic particles cease to move, i.e. water freezes at 273K and boils at 373K). So if it's a measurement of temperature, what difference would it make what K bulb one gets?

If there is a difference, I've searched, then searched again for a lower K power-compact bulb, and I've found them. But those are Actnic bulbs and I wouldn't want to replace a bulb that I already have in the first place.

 

[Silly me]

a light that is rated in kelvin compares the color of the light to a black media heated to xxxxK at 10,000K the color of the black media ( mostly carbon ) seems very blue but at 2700K the mostly red same as cheap incadesent bulds..
The sun is rated at 5500K plus the amount of blue light reflected by the sky a rateing of 6500K has shown to be the best compared to the light a plant would get outside..

A plant absorbs mostly red and blue light 600-700nm and 400-500nm so a 10,000K light might have a lot of both but not much green 500-600nm it grown plant very well but leave the tank looking purple..

personaly I like any light between the 5500K and 6500K as it shines a very white light, making the tank look great and has a very good amount of plant growth aswell.

 

[Nospherith]

Okay, so I think I understand. So the extreme lower K bulbs are reddish, and the higher K bulbs are more bluish. So the K basically has to do with this light output chart seen here:

This seems okay (not perfect but I guess it will work). At least there's some blue and green/yellow spikes happening. Better than none of those spikes I guess.

 

[opiesilver]

I agree only partially. The is a difference between 10K actinic and 10K daylight bulbs. While your description is true of the 10K actinic, the 10K daylight bulbs have a very white look to their light.

 

[Lateral Line]

Actinic lamps are pretty obviously blue, also pretty power hungry, normally you need a more powerful starter to flash an Actinic lamp. 10,000K of whatever type is still not ideal for freshwater tanks.