I hope i get this right. and i wont be offended if i'm wrong but don't badh the heck of out of me...

alot of the 6500k will make its way down there its the color that pushes it to the bottom so if you look at the 20 K color its has to filter out is color to make it to the bottom. Because I believe and some one can back me up on this or help me out blues are the first color to go, when its in the water. IE as you go thur the leve lof water.

And Yellow /white hardly hasa nay color to defuse thur the waves of water.

So the lower K rating will break longer thur the water then a 50 K or a 20 K

a lot more than the 20K bulb.. just because the PAR is higher to start with and 2 feet of water isn't going to make a difference.




In 80 feet of water nope.. what you got to under stand is that the blue is not filtered out as fast as other colors of light.. so think of it this way .. even a 6500K iwasaki has a huge blue component to its spectrum.. that blue will make it just as far if not farther than the radiums or XM's 20K as it is more intense to start with.. now talking about our 24" tanks.. doesn't matter not going to cut out enuf to be significant.




Is this a new 20K bulb as the old test results showed that the 15K put out more.. but at any rate.. 15K and 20 are not accurate there 20K is probably about 17K and there 15K is probably about 16K in reality.

a AB 10K has an actual color of 13.6K and will blow any bulb on the market out of the water if run properly.. so don't get all hung up on K values as for the most part it is a misleading number used for marketing.. I had one companies bulbs here a 10K, a 14K and a 20K.. the 10K was a very impressive bulb with a decent look and a very high PAR output. the 14 and 20K bulbs you could not tell the difference in by looking at them but a camera could pick it up.. very slight.. I would say 500K to 1000K real life difference at most. but they were also both about 1/2 the Par of the 10K at the bottom of my tank so 24" of water plus 8" of air.

personaly I would like to get ahold of one of each of these new bulbs and run some par test like I did a coupld years back but I am not in the finantual position to blow 600.00 on bulbs I don't need. Now if anyone wants to loan or donate some different bulbs we can do some used comparasons on aged bulbs and see how different bulbs hold up.

also just because a bulb looks blue don't assume it has a higher blue output than a bulb that looks crisp white.. that crisp white bulb is usually a high (very high) blue spike, with just enuf green and red to make it look white.

but we shoudl leave Bob's thread to his Nano and continue this in a new thread of you want to discuss more on this.


Steve

got it back wards buddy, blue (longest visable wave lenght is the color that will go the deepest.. red will strip first, then green then finaly blue, but like I said in our 24" oceans it doesn't matter much. the trade off for having a blue bulb is lower par to start out with and corals will adapt easily to using the other colors that are with in the PAR range.

so if you like the blue look use blue bulbs, if you like the ice blue look get good 10K bulbs with VHO actinic.. if you like the white look use 10K's.

Steve

Thanks Steve I knew it was somthing like that ..

mike

so after all that nonsense do the cosco lights have proper spectrum or power to properly keep corals under?
im shure the fish could care less, but is it a good choice to not use lighting made for a fishtank instead of nightstand?

yes they will work fine.. they are a daylight bulb so they are the right spectrum.

Steve

if they had something stronger it might be a sweet sump light to save some money

where did you buy that tank?:P all glass?