Dana and John, I would like to thank you, and both Mr. and Mrs M. Clark for giving me this opportunity to interview you and be given a tour of your facilities. I appreciate the fact that you showed me "everything" and did not place any restrictions on areas that were off-limits and that you did not restrict me either from taking photos of whatever I wanted.
This speaks highly for your company.
I was extremely impressed with the cleanliness, well laid out systems, laboratory and equipment, instrumentation used, methodologies applied and so on. I have rarely, if ever, seen an operation of this caliber. No wonder your success rate is as high as it is.
Not only were the "trimmings" there and present to a degree far greater than what one would expect, but the results of all your efforts were visible in the success rate you are obtaining with the techniques you are utilizing and implementing. Over the years, and you know that I have been around for a while, I have seen hundreds of pet stores and hundreds of breeding facilities. Yours is miles ahead of where every one else is. I say that because I have seen it and am able to compare. Nothing else even comes close to what you have in Cleveland TN.
I was a real pleasure meeting Mr. and Mrs Clark and getting to know them better. Thank you for your very kind attention and the time you took to make sure that I had access to everything I wanted to see and document. Thank you too for letting me interview Dana and John.
It is really gratifying to see that with the right approach you have set the hobby one large step further: propagating corals and fish in captivity with a degree of success that you can truly be proud of. I wish you all the best in your endeavors and am convinced that once more hobbyists and stores become familiar with what The Aquatic Wildlife Company is all about, you will be recognized as one of the leaders, if not "the" leader, in the advancement of the hobby.
For those who read this and wish to visit, which I strongly suggest and highly recommend, the phone number is (423) 559 9000. This coral propagation and research facility is definitely worth visiting. If you do so you will be amazed by the quality and diversity of livestock being offered for sale.
The photos I took will be added to this TT site section as soon as they are returned to me by the processing firm.
Interview Part I
Dana, in your presentation at the Western Conference in Las Vegas you gave a lecture on lighting and on PAR, a summary of which can be accessed from Summary of Dana's Talk in Vegas. Could you briefly explain how this is different from the way in which hobbyists have been looking at lighting in the past.
It is certainly my pleasure to be here and to be able to discuss some of the concepts introduced during that conference, and answer other questions you may have.
P.A.R or PAR, stands for photosynthecically active or available radiation. What it is, in simpler terms, is a measure of the energy that plants and algae use for photosynthesis in the 400 to 700 nanometer wavelength range. It is, actually, a term that coral and plant biologists have used to describe the energy that is used in photosynthesis. Unlike other measurements, it allows a researcher to compare apples to apples when measuring lighting efficiency. It is by far a better measurement than any other ones that one finds mentioned in hobby literature and allows for comparisons that are valid and can be compared against each other.
The summary of my talk lists a number of light sources that are used in the hobby and gives more details on how each of these lighting sources actually performs in terms of providing corals with a certain amount of PAR. I acquired a PAR meter to be able to study the many types of lights now on the market and actually measure what their PAR was, as opposed to what anecdotal evidence about these lights would have us believe.
The major difference between the two year research project that I undertook were all done measuring PAR of artificial lights. That is unique in as much as most studies performed were done in the field, using the sun as the lighting source and measuring its PAR in various areas, depths, regions and under various conditions.
The results of this study are vast and I have only briefly touched on them during my presentation in Vegas. Let's face it, in less than an hour one cannot cover very much. Nevertheless I was able to draw the participant's attention to this new way of looking at lighting energy and its importance for the corals we keep in our aquariums. To my knowledge such a study has never been undertaken and I am still analysing the results to draw more conclusions from them.
PAR will in my opinion soon become the standard way of looking at light and will be used more and more frequently. It is a far better way of gauging lighting and its efficiency than measuring lux or looking at lumens, or even going just by the spectrum of a bulb. We should not overlook that the spectrum changes, rapidly for some bulbs and less rapidly for others. What may be an excellent lighting source when new, may not be so after a short period of time. I have given some details on these changes in the summary that you have already added to your web site.
If I understand what you are saying correctly, PAR is a much better way to look at lighting efficiency and efficacy, than just looking at the spectrum. In a way you narrow the wavelengths emitted down to those that are most beneficial to the corals and pay attention to those when deciding on which lighting is to be preferred.
Yes that is correct. It is my contention that we should concentrate more on the effective intensity (PAR) than on the spectrum itself or alone. With the array of lights now available it becomes more important to focus our attention on those bulbs that provide the energy (also called photon irradiance level) that corals can effectively utilize. 10 K and 20 K Kelvin degree bulbs can certainly be used in some applications but I find that out of all bulbs now on the market the one I prefer is the 6500 Kelvin one.
It has excellent PAR readings and corals react very positively to the radiation emitted by that bulb. Our focus should be more on the amount of photosynthetically useful radiation than just on lux. If the PAR is low even though the lux is high, corals will not benefit as much from such a light than if the opposite were true.
Does that include looking at the fact that certain types of wavelength provided in greater amounts, can result in the same effect as other wavelenghts provided in far lesser amounts. What I mean is that one can achieve the same result by providing high amounts of PAR using a bulb that emits more of a particular desirable wavelength that is high in the wavelength corals can utilize.
Yes that is correct and several studies have been done in this area (with sunlight I need to add) that indicate that the type of radiation we should provide is the one that corals can indeed utilize and, in addition, ensuring that we provide enough quantity of such radiation. This has an impact too on pigmentation of corals, which is another area that we are looking at at Aquatic Wildlife. I will have some data available on this in the near future as I continue to monitor what exact wavelengths provide the kind of PAR that corals need for growth and also for pigmentation.
Pigmentation is an issue with both LPS corals and SPS corals but much more so with the latter. I have had excellent results with some of the testing I have done, applying and providing what I have found to be the wavelengths that promote faster and better or more intense pigmentation. I need to do some more work in this area and will then release the data.
Intensity or brightness is not an important factor if one provides the wrong wavelenghts, even in large amounts. The key to success is to utilize lighting sources that emit the desirable wavelengths and those are the PAR ones. Anything that falls outside of that range is really of no use to corals and will not promote growth or coloration.
To be able to conduct research in this area it is important to be able to have a standard that one can use across the board when looking at different types of lighting. PAR is definitely such a standard and will, hopefully be used more and more by hobbyists as well, not just researchers.
Is this research directed more specifically to SPS type corals or can this be applied to LPS corals as well.
It really applies to all types of corals but the research we are conducting now is more geared towards the SPS types as they seem to develop more coloration when exposed to light sources with the right PAR levels. We will be looking at LPS corals as well of course as many hobbyists tend to focus their efforts on such corals. Providing them with data based on research in that area is therefore important to us as well. As I continue my research I will be able to make recommendations in those areas as well.
It does remain a fact though that if one wants color in an aquarium that it will more than likely come from the presence of SPS corals and to a lesser degree and with some exceptions (Elegance for instance) from LPS corals.
Because of the large number of species of corals on the market and the large array of bulbs being offered, what kind of advice would you offer to hobbyists in terms of what lighting to use.
I would recommend that the hobbyist use the 6500 Kelvin degree bulbs. The longevity of these bulbs appears to be pretty good and they develop a good deal of PAR. We are using those in our research facility and many corals really get magnificient coloration under these bulbs. If the hobbyist wants to experiment with the 10K and 20k Kelvin degree ones, they can certainly do so but it is my strong belief based on the research that I have done and am continuing to do that corals can be kept under 6500 Kelvin degree bulbs with great success and with real nice colors developping.
What is your feeling in this respect with regard to VHO bulbs?
Yes those bulbs develop a good deal of PAR and if the hobbyist want to keep LPS corals that is certainly a bulb to consider, providing enough of them are used. They can certainly have success with those bulbs and would be a good bulb to begin with. The results obtained with 6500 K ones though are far better and a larger amount of PAR is emitted with the beneficial consequences that go hand in hand with this.
Although you rate them as good, you do feel that they are not the best way to go, is that correct?
Yes that is indeed so. They do not develop anywhere near the amount of PAR developed by Metal Halides. Even though PAR is better than with other bulbs, MH ones produces a far greater amount and result in better success with coral growth and coloration.
Since we are talking about MH bulbs, quite some time ago, over a decade really, Osram HQI's used to be a popular bulb. Have you experimented with those types as well.
Yes I have looked at those too and although they produce a great deal of PAR, they produce a great deal of ultraviolet radiation too. If the hobbyist wants to use those he or she can do so but a shield will need to be used to filter out the UV. I would recommend the use of Plexiglass UF-4 to eliminate the unwanted UV radiation. They are excellent bulbs or light sources but because of the large amount of UV produced the hobbyist must take precautions there and definitely use shields to filter out the noxious UV.
Are you saying that what we have adhered to for some time, to be more specific, that we need some UV, may not be entirely correct and that UV is not all that important in reality.
Yes that is correct. Our research indicates that any wavelength below 380 nanometers is not desirable and is not required for coral growth and coral coloration.
Would that exclude the use of Actinic O3 bulbs which are quite popular among hobbyists.
Actinic O3's actually produce very little UV radiation. I would recommend that bulb if the hobbyist wants to provide more blue, for instance in conjunction with a 6500 Kelvin degree bulb.
Would it be a good idea then to use Actinic O3 and if so for what corals would that apply?
It is in my opinion not necesary to do so but a lot of hobbyists like the additional blue that these bulbs provide when used with 6500 K MH ones. It is in my opinion a matter of personal preference and can be used for both LPS and SPS corals but, as I indicated, it is not really necessary.
Would you say that hobbyists use O3 bulbs because just about any book they open that deals with lighting tells them to do so. In a way they are led to believe that these bulbs are necessary because the literature stresses their use so much.
Our research indicates that they are not really necessary and that when used they mainly are because of the perceived aesthetic value they bring to the aquarium. From a PAR standpoint they are, based on my findings in regard to growth and coloration, not necessary but hobbyists can certainly use them if they feel so inclined.
It is interesting to note Dana, that I have never been an advocate of using O3 type bulbs, and you seem to confirm that what I recommended purely based on observation of corals, now pans out in terms of research.
Yes your early observations were indeed correct, and we have had that information for years but have only now through research been able to demonstrate that what you were writing was indeed correct. I have been a avid reader of your writings and find that in many areas you have certainly set the stage for what we can now prove through testing and research.
Thank you Dana, this concludes the portion of the interview dealing strictly with lighting. The next area I would like to get into is recommendations to hobbyists who keep, or plan to keep, SPS corals.
Ed. Note: this material is on tape and will be transcribed and be the topic of the next document in this series of articles on my interview with Dana and John.
Again my sincere thanks to the Clark's for allowing me to question you without reservation and without your having to withold any information from me.
The next article in this series will be available very soon and I will use our mailing lists to let readers know when the second document of many more come is active on our web site http://www.athiel.com
Copyright Dana Riddle. This article may be reproduced on on other web sites providing it is referenced back to http://www.athiel.com and The Aquatic Wildlife Company Banner link on the main index page of that site.