On a frag tank, most people want really good color so that is why I went to 2 actinic. There is no denying that better color comes from the actinic bulbs. They make more colors fluoresce than the Blue bulbs do. 2 purple may be a bit much but I wouldn't run 2 coral plus either unless you want a very icy-cold look to the tank. As I have been messing around with all my bulbs lately, I had to come back to the purple plus to warm the tank up. The Coral Plus is just too cold on its own. ed.
This is very deabatable. Ro me a fgrag tank is a tank where you take a small cutting from a coral and try to grow it into a new coral. For many of us growth is the key wlwmwnt we are looking for in a frag tank.
Now if your selling frags comercialy then you have a compoletly different situation. Tour trying to get the customer to vission your frags with the best possible color so that he will think your frags in his tank will look getter than any of his existing corals and he will pay premium price for your frags.
Actualy I knew a retailer had show/frag tanks in his main store with 20,000K mh's and atinic VHO bulbs for display, and in the back he grwe ius fargs with simple Ushio 6,500K MH bulbs wherw the customers could not view them.
So it realy comes out to a definition of hat you consider a Frag tank.
On your comments on Atinics not burning out in a long period of time I will say this is probably true of more bulbs than than just atinics. On my fresh water tanks mostly planted I had run most of my bulbs for many years. Some of them would loose 20% of there light over 3 to 5 years but none went dark on me. True if I evaluated there spectrum I probably would see a shift but for fresh water usage that shift was not extremly detrimental.
But my question is how does one realy determione the PUR of a light source with corals unless you look at each type of coral in the tank specificly. How many of us have light spectrum anaizers? And even ifwe did how much do een the so called ezperts realy know on what is dieal for any specific coral. Sure we can say that 450nm light is more ideal than 680nm light is on a said coral vut do we know for sure that if we lack light at 450nm we can make up the shortage with light more light at 460nm? Or in the case of Atinics with 420nm light?
Several individuals have made extensive studies on the florescent "pigments" in corals. They have made charts listing the excitation wavelenghts as well as the wavelengt the pigmens generate. Yes there are some "pigments" listed in the 420 to 420nm range. Some even go as low as 380nm but on the other end of the spectrum a few also go into the 600nm range. Some "
igments" can be excited by different wavelenght and return light back to us at different wavelenght dependent on which they were excited at. But a majority of the "pigments" are excited in the mid 300nm range.
Why do the atinics look so good then? well if you had a light source in the 410 nm to 420 nm with no light emited below 400nm or above 430nm it would be varely visable by the huma eye and unless it was extremly intense would look very dark. But if there is any pigments that take that are excited at those wave lenghts they will emit lightat a longer wave lenght that the eye is is more sensativce to. So that dim 470nm florescense pops at us because our eye adapted to the lower light of its surroundings.
Now your start adding additional light in longer wave lenghts like the 470 nm Blue Plus light and the surounding start looking brighter and the contrast between the florescent light at 470nm is less noticable. But now we also have stronger floresense poping up at longer wavelenghts crom other pigments at perhaps 390nm to even 608nm. Even those there floresense are stronger they do not appear to the eye that way because the backrgound is brighter.
I had done experiments with LED's on this florescens and RT you can do the same now that you have a LED fixture that is tunable at different wave lenghts. Light the tank with only a narrow band width of light and see what floresses and what does not. Look hor the same foral floresces at different colore from different wave lenghts of light it receives. If you have the smae corals I have you will note that the max florescense is from light at 455nm floowed by 470nm, then 450nm and finaly 410nm wavelenghts of 490 and higher being the least. If you have frogspawn you will see if floresses yellow from 310nm light, lime green from 430nm, green from 455nm, cyan from 470nm and almost blue from 495nm light.
