Has been doing some tests with another lighting. The reasons is two. My PS Hyperion metis SMT gives a light pattern that I love and my corals seems to thrive but the PAR readings at the bottom rather low (80 -100). This fixture has no phosphorous coated LEDs (no “white” LEDs). To give the aquarium a white looking – the fixture user the RGB technique to trick our eyes (or brain). To use RGB technique (as many “white” t5 tubes do) to mimic a white light has some advantages according to the colour of the corals. Many corals has fluorescence – it means they act as weak light sources sending out photons of another wavelengths (read colour) compared with the incoming photons. Because of the construction of our eyes (brain) - too much of the wavelengths between 500 – 600 nm will block our ability to see these weak colour sources. Many people run heavy bluish tanks in order to get this “poops” of the corals. The disadvantages of using very much of blue light is that you get dull fishes. Their reflecting pigments need “red” photons to show red, “green” photons to show green and so on. To use more RGB oriented light sources will partly resolve this problem. Not as good “poop” as with “all” blue – but much better comparing with using light industry adapted phosphorus coated LED of low Kelvin. However – this approach will lead to run much more intense red and green wavelengths than normally is accepted in the hobby. There is 1 (ONE) article according damage with red LED to corals – this article has been the leading argument for not using too much red (and green) wavelengths to corals. Yes I know that most red has disappear from 5 m and down but that will not exclude that red can be used by corals. My experiences with my aquaria contradict the conclusion that too much red wavelengths will harm corals (and green).
The second reason for testing a little different light is the growth pattern of my corals. Especially my bird nests. Because I use LEDs without any phosphorus coating – my fixture gives zero or near zero of wavelengths over 680 nm. Far red (around 720 nm) has in plants shown a very important ability to change the growth patter to a more slender form. I have taken birds nest from a tank with lot of far red (MH lighting) – the coral is rather slender with rather few branches with a normal space between them – one to two weeks in my aquaria - they begin to branches in dense patterns – se the pictures.
The base has been grown in the other tank – tops during 3 weeks in my tank. My pH is in average a little bit higher but my PAR is lower.
The same coral - 1.5 years in my aquarium
In order to test if 720 nm has any importance for the growth pattern of my corals – I borrowed a test fixture constructed by Heliospectra in Gothenburg. However I need to have a little higher up (the spread is to narrow for the moment – and I was not pleased with how my corals and fishes looks like. I have to do a little more work before starting this fixture.
Instead I got me a T5 fixture and mount in front. I use Red sea´s 22 000 K and 15 000 K tubes.
The results is lighter, now 140 PAR at the bottom near the front window. After studding the spectra’s I have decided to test a pink T5 tube – it has a little peak around 720. For the moment – one actinic and one blue white tube. 2* 54 HO T 5 tubes
Interesting spectra for those that still believe that T5 tubes is a full spectra source
Actinic 22 000 K
Blue White - 15 000 K
Pink
Sincerely Lasse
