how much atinic?

[StirCrazy]

Originally Posted by asmodeus

I thought that you need actinic on the tank for the corals to grow

no you don't nessasarly need actinic light for corals to grow. what you need is light in the PAR range. This is the light that causes photosynthic activity in algaes, plants, and what not. But it just so happens that what we commenly call Actinic light, falls with in this range of spectrum. basicly you need light between 380nm and 780nm, and actinic falls in around 430nm. Because water filters out red and green light befor blue DEEP water corals have adapted to using the lower end of the PAR spectrum. Now if you go in the shallow reef flats you will probably more acuratly reproduce the natural light with a 10000K. I would say even a 6500K but I feel even a few feet of water is enuf to filter out some of the red light leaving you with closer to 10000K.

if you use a full spectrum light like a 6500K bulb there is a quite large actinic conponant so you will be alright just using that alone. although it will look like some one peed in your tank

My theory on spectrum is to use a good 10000k and suplement to taste with actinic.

Steve