Well, I think the first thing you need to do for your tests is to establish a control tank using basic, ordinary bulbs. That's what we here have done and that's why we, after using different bulbs, after more than a decade, can report that there has not been any meaningful differences in growth performance, regardless of the type of bulb used. The reason is that there are many more important factors influencing growth performance, such as CO2 and nutrition, that far outweigh the influence of the bulb type being used. There may be colouration differences here and there, but there will not be a measurable difference based on spectra. In fact, it would be easy to see a difference in several tanks using different spectra and to then conclude that the differences were due to spectra, when in fact, the growth differences would be caused by variations in CO2/flow/distribution between the tanks. I supposed the tests would need to be performed multiple times so that the resulting data would be statistically relevant. At the end of the day, it won't really matter.
I have no idea about the specifications of BML lighting and just because Dennis Wong is using it that does not mean it is superior to other lighting. Dennis Wong is skilled enough to grow plants successfully using whatever lighting he chooses, so again, any BML Lighting testimonial means nothing more than typical hyperbolic marketing. One first has to be able to grow plants successfully regardless of the lighting technology in order to even begin to assess the impact of any spectral conditions. Have you accomplished this? Have you consistently produced planted tanks that are problem free? Have you been able to address problems in the tank and resolve them properly? Investigation of spectra before this task is tackled is putting the cart before the horse.
It seems to me that you have had problems in your tank and have immediately decided that the cause was due to spectrum while at the same time we here at this forum were advising you that no, your problem was due to insufficient nutrient, or CO2, or other factors that needed to be addressed. You chose however to use information from other websites that specifically offered advice to the contrary. Whether your problems were resolved is not clear.
Obviously you are free to carry on any experiments you wish, using any data you gather. No one disputes that. What many here object to however, is that our advice and information is immediately discarded as being faulty in favour of information from other websites, which you report as being more reasonable. Again, you have the freedom to follow any path you desire, but we also have the freedom to dispute the validity of the data presented in those other websites. Know this however; for many years we have investigated the topic of spectra, and while I now find it a tedious, certainly others may find it fascinating as you do, but the fact remains that test methods have to be stringent and above all, the method of control is paramount. You have not yet demonstrated an ability to consistently establish a control tank, i.e., a problem free tank.
I repeat our position that a bulb's spectra has little or no bearing on plant growth or health compared to the effects of other factors in the realm of plant husbandry, such as CO2, PAR, nutrition and flow/distribution and spectra is certainly nothing that algae care about. With the exception of a few species, algal blooms are a direct result of nutritional deficiency syndromes that result in poor plant health. The species of algae that occur are a direct indicator of the deficient nutrient. Algal blooms are not a phenomenon that can be resolved by changing spectra, however, reduction of PAR has been shown to help alleviate the bloom.
Cheers,
Any insights into the dreaded cyano can only be a good thing AFAIAC.
