I normally have much redder (especially 660 nm) than reefers have normally. The 735 I ad for the moment is very local – it is luminating only a small volume of the aquaria. 735 do not penetrate very good into the water. Measurements that we have done show a more than 60 % tap already at 30 cm depth. At 100 cm depth – the tap is more than 95 %. The question has always been – can wavelengths higher than 700 have any importance for corals out in nature? Probably not, but have they lost/developed this ability despite the facts that these wavelengths disappear already at 1 m depth? With my gut – they do not have this ability to alter the photosynthesis with help of the Emerson effect - why should they? But gut and sciences is two different things and there is indications – at least for me – that these wavelengths can have importance in aquaria (there depths seldom exceeds 70 cm)
It has recently been showed that the saltwater plant eelgrass (Zostera marina) has lost the genes for the Emerson effect and should be rather interesting to know if this is true for corals too. In short – as I have understood this – the Emerson effect helps to optimize the photosynthesis and the cooperation between the two photosystems (680 and P700 – photosystem 2 and 1) And if it exist in at least some corals – it can explain some odd experiences off different light that I have there rather low PAR levels give some bad results according to burned corals
During the last 10 – 15 years I have seen many aquariums with different lightings and I have to say that it has looks like MH it’s a little bit outstanding compared with only LED to promote growth. Have in mind that I´m a person that have been working with LED for a long time and is a strong LED believer, but I have to admit this. There is also evidences that T5 tubes is effective to promote growth. And also, some LED systems.
Myself – I have a system without white (phosphorus coated LEDs) because I want to see the beautiful fluorescence of many corals without having a total blue aquarium. The growth is good, but I can´t understand why this 3*145-Watt armature not give me 3 times better results that I got from my 3 pcs of Coral Box Moon LED at 54 watts each. In reality – I could not run this at full effect without to burn some corals at the top. And I know a lot of people that has this experiences with this armature – they are more powerful that the watts say and what the PAR readings say. In this armature – it is a white 5 watts Cree LED.
T5 bulbs (the modern type) is not a full spectra lighting system – basically – there is a blue top, a green top and a red top. They content a lot of red – without gotten the rumour that red kill. Many of them also have some wavelengths around 736
MH give a lot of wavelengths between 400 and 700 but also a lot of far red and IR radiation
I notice a rather wired adaption of my S.hystrix when I introduce them into my aquarium from an other aquarium. The growth pattern gets enchanted. In the first aquarium – a slender growth – MH with far red) – in my aquarium without ant wavelengths over 700 nm – a bushy growing pattern. In another aquarium – with phosphorus coated LED and hence some far red – the growth was something between – and the these two aquariums had the same water.
The question is - can 730 nm change the speed of photosynthesis and make it more effective?
Another question – is green light important for the growth rate and photosynthesis? It’s true that there is no type of chlorophyll that peak at these wavelengths we call green and that a green plant is green because the photons is reflected. But its also known that there are co-systems that can pick up different wavelengths and transfer them to usable quanta so green is maybe not the most effective wavelengths but in some way, they are linked to the photosynthesis. Its known – from terrestrial plants that green can penetrate rather deep in the tissue and hence provide some help for the photosynthesis in deeper layer.
There is also some prove for green photons can go trough leaves and hence make some photosynthesis rather low in the canopy. I got an idea – I can test that. I took my headlight (a strong phosphorus coated white LED) and hold it above a rather thick green leave from one of my wife's potted plants. The result you can see in the pictures below. From the upper side – there is reflecting many green photons – because the green colour of the leaf.
But how its look on the backside of the leaf – there is no light or reflected green photons there. If all photons are reflected (green) or absorbed (all others) it should be black on the backside. If the backside has any colour in this experiment – it means that the photons of that special wavelengths (read colour) has travel through the leaf – look self for the result.
I have never, ever before proved a theory so easy as I did in this case. Green photons can travel through plants cells in a way that others do not! It means that leaves further down in a tree can use green wavelengths – the red and blue is already absorbed.
Has this importance’s for stony corals – I think so. If it can travel down in a cell structure – it can work in the deeper layers and be reflected of the white skeleton.
I hope you can follow my thoughts above and get an idea why I think that its important to investigate this.
We will do some experiments with monochrome wavelengths of 400, 420, 450, 535, 630,660 and white phosphorus coated LED of 6500 K. During a certain time we will measure the oxygen production of (in the first run) S.hystrix and link this to produced oxygen/gram coral. We have got some primarily results, but we are also rebuilding the test apparatus according to results and with help of other persons with high knowledge of this to do a good test with reliable results. Its to early to say anything yet but we are going to publish the results here at R2R when we think that we can stand for the results
We will also investigate if there is a Emerson effect within corals and for every tested wavelength
Sincerely Lasse