replacing RB with TV

[cocojakes]

I've noticed that unless you have a lot of TV in a build, you don't notice the effects hardly at all once you turn on the whites, what if you were to swap the ratio, so instead of 2 RB, 1TV, 1NW you did 1 RB, 2TV 1NW?

 

TV is a powerhouse as far as par, and even the white has a fairly large 445nm peak, is there something I'm missing, or do you think this would allow me to really bring out the fluorescing without having the tank super blue, since the TV doesn't affect the colour we see in the tank much other than the fluorescent spectrum.

 

Any input, positive or negative, I'm tempted to give it a try to find out unless someone has some big issue I'm overlooking?

 

 

its for the new 20 long build I'm planning, I would use the same led layout as is suggested on uglybuckling's thread, but use the new TV 3up chips instead of the royal blue 3 ups, and use regular royal blue chips instead of the regular TV chips

in this pattern:

[cocojakes]

maybe this would be a better idea, just to add extra TV that way the RB is still close to the NW so that it minimizes disco

[evilc66]

When using violet, you always want to add to what you have. Replacing royal blue with violet is going to mess with your overall color temperature. While royal blues offer a lot of growth potential, they are also the backbone to the basic reef light setup, raising the perceived color temperature to the point we are more accustomed to.

[cocojakes]

When using violet, you always want to add to what you have. Replacing royal blue with violet is going to mess with your overall color temperature. While royal blues offer a lot of growth potential, they are also the backbone to the basic reef light setup, raising the perceived color temperature to the point we are more accustomed to.

maybe I should have phrased the title differently, I meant more swapping the ratio, so instead of 2RB : 1TV doing 2TV : 1RB, but I ended up doing a 1:1 ratio of TV to RB. Part of what I am trying to achieve is ample fluorescence without the colour temperature being too blue. I plan on having everything on dimmable channels so I can adjust it to my liking anyway, but if I end up with TV at 100 and RB at 50, then why not just use less RB.

 

currently the plan is 3 pucks of LED spaced about 9 inches apart over my 20 long like so (4 channels going to a storm controller)

 

[evilc66]

Be careful. You already know that violets are PAR monsters. As a result, adding enough violet to start noticing the fluorescence from them will put your PAR levels through the roof. Anyway, most of your fluorescence comes from light in the 440-500nm range (with some outlying exceptions).

[fishnlou]

I have messed around with this idea and my personal opinion is that it just leads to a dimmer looking tank over all. This is due to haveing less royal blue which = less white to achieve proper color temp. It does produce a slightly better coral floresence, but in my opinion its not worth the dimmer look of the tank. As you stated true violets are par monsters and I was frying corals with a overall dim looking tank.

[cocojakes]

well each colour will be on a separately dimmable channel, so if its too much I can dim it, but I just want to make sure I have enough of everything that I can dim everything to my desired look, and not wish I had more of a certain colour when I have everything where I want, but one channel is maxed out and still not enough of that colour, you know what I mean?

[evilc66]

Yeah, I know what you mean, and you are heading in the right direction for that. It's just that in your previous statements, you made it sound like you wanted to add enough violet to start seeing fluorescence from it, which is a bad idea. Violet should strictly be used as a PAR supplement and nothing more.

[BradVincent]

I thought of this, and don't think it is a bad idea, but would be too expensive for my tank.

 

Most white LEDs have a sharp peak at 450nm, which is also where RB peaks. This is not a coincidence, most LEDs are white, and most create white by using phosphor which is activated by 450nm. RB Leds are just white LEDs without phosphor, marketed toward designers of fixtures that have their own phosphor.

 

Using RB and white together gives a HUGE spike at 450nm with very little else. It isn't natural. The Radium 400 watt 20k Halides also have a HUGE spike at 450nm with very little else, so that isn't to say it doesn't work. Putting more energy into the 420nm-450nm range and less into the 450nm should give a more natural spectrum with more florescence.

[evilc66]

More natural spectrum? Yes (but that's very subjective). More fluorescence? Not really. Fluorescence occurs across a wide range of wavelegths, not just 420-430nm. Most fluorescing proteins are excited by the 440-500nm range, but there are some proteins that will even fluoresce up into the 600nm+ range. It's all dependent on the corals in question. Just adding 420-430nm light will not magically fluoresce things better than 450nm light. Only the proteins that are excited by 420-430nm will take advantage of it.

[cocojakes]

currently the thought is 2 pucks, each one consisting of:

 

channel 1- 1x luxeon M 4000k 12W

channel 2- 1x luxeon 480nm, 1x luxeon 495nm, 1x luxeon 660nm

channel 3- 6x luxeon 445nm

channel 4- 3x semiLED dual core 3W 420nm

 

does that sound like a reasonable amount of light, two of those pucks over a 27x12 inch area (12 inches deep, no optics) all of them running at 700mA with PWM dimming.

[BradVincent]

More natural spectrum? Yes (but that's very subjective). More fluorescence? Not really. Fluorescence occurs across a wide range of wavelegths, not just 420-430nm. Most fluorescing proteins are excited by the 440-500nm range, but there are some proteins that will even fluoresce up into the 600nm+ range. It's all dependent on the corals in question. Just adding 420-430nm light will not magically fluoresce things better than 450nm light. Only the proteins that are excited by 420-430nm will take advantage of it.

It would be more technically correct to say it will give us a higher ratio of fluorescence to other light, as visible to humans. A very bright 420nm light looks very dim, especially compared to other LEDs. So if anything fluorescences in the 420nm-430nm range, the amount of perceived fluorescence increases, while the amount of perceived other light does not.

 

A tank lit just by 450nm will show a lot of fluorescence, but look purple/blue. This is the 'actinics only' tank we sometimes see. A tank lit just by 420nm will have more of a "black light" effect.

[Horerczy]

Well a black light is ~380nm usually so it makes sense the 420 will look similar.