[charles matthews]

Randy: about nutrient addition to increase heavy metal uptake, blue-green algae will fix nitrogen. Adey makes the point that, as nitrogen levels fall to seawater values, there is a succession of species on the scrubber to blue-greens as they begin to fix nitrogen. I have not worked with scrubbers myself yet, but this seems reasonable, so I presume nitrogen would not be limiting. With the enormous number of species available for competitive succession, one might be hopeful that selection would occur to possibly select for optimal species for uptake of limiting phosphates and heavy metals. Since it appears that iron is not limiting in your tank now for driving heavy metals down further, it would be nice if levels of heavy metals could be driven downward without the additions of nitrogen (which might raise nitrates). On a scrubber which had reached a blue-green dominance consistant with low nitrogen levels and measured low phosphates, addition of iron, silicate, iodine, and phosphate in a tank with a large scrubber might be optimal.

I'm going to suggest to theEco-Wheel people that they submit some test data to the lab you suggested, without fertilizer initially to try and replicate Adey's data- possibly in collaboration with him- and to the Inland Aquatics people. They have a lot to gain by this if it works.

Similarly, I am wondering if there would be commercial motivation by the Ecosystem people to submit data, without and with fertilzation, to try and solve this problem.

This gets at a general problem of lack of experimental method in this industry- which you and some of your colleagues have been working hard to solve. I am wondering whether an article defining the heavy metals problem as something of a challenge to the aquatic plant filtering manufacturing community, requesting independent data about this, might be achievable. An effort to to force manuracturers to begin respond to fundamental questions, well formed and posed by aquarists, is needed. Perhaps we should be doing more than talking about this.

To summarize

1) More experimental method is needed. Rather than leave this on the backs of yourself, Shimek, Bingman, and a few others, it might be possible to form a committee through Reef Central to submit well-formed questions such as this to manufacturers and request independent research. Such manufacturers would be recognized as supporting research.

2) I am going to contact Eco-Wheel about the requested copper levels. If they are not willing to subsidize it, I will do so. Water samples may be best sampled from an independent aquarist.

Thanks for your thoughts!

Charles