Hi mate,
Well you see, the marketing departments of companies lie all the time. Just have a look at any advertisement on the tele or in magazines. How about that latest shampoo & conditioner? Will it make your hair really look like that of a supermodel, or did they just hire a supermodel and spend thousands of dollars at a famous hair designer and then shoot the scene of that lovely flowing hair with top notch photography? Is that top notch toothpaste brand really any better for your teeth than the Tesco brand, or does it simply come in a prettier, multicolored, sparkling tube?
The world is built on a foundation of lies. So much so that people are no longer able to discern fact from fiction, and this confusion is a perfect breeding ground for selling product. Since the consumers are presumed imbeciles I can lay any marketing idea out there and because it's on a fancy label paraded down the runway by a Top Model then it must be true.
Look at this excerpt of a clever product description from Profitos Trace mix fertilizer:
The supply of nutrients in ProFito is so optimal, that plants will grow fast and strong. Thus unwanted compounds in the aquarium, like certain nitrogen and phosphate compounds, will be taken up by plants quicker. Nitrate, phosphate and ammonium are removed faster out of the aquarium water by the plants. This way the water quality is well supported by the usage of ProFito. Moreover it improves and maintains a better biological balance in the aquarium.
Of course ProFito does not contain nitrate or phosphate...
So NO3/PO4 are described as "unwanted", and their "removal" from the water column is advertised as some sort of fringe benefit of using this product. The Ad implies that it's the trace elements alone that are responsible for growth performance. I mean, we know this to be total rubbish. We know that it is NPK that are responsible for growth performance.
OK, so in the case where the substrate was not Amazonia, is there any indication of what specifically the dosing program was? Do we actually have a factual account of whether the tank was, for example dosed with extra pumps of "Lights"? Do we know what the CO2 injection level was? How about the content of the water, was it tap or RO? How long did it take to produce the resutls that are being advertised. If you look at some of the brilliant low tech tanks by Dusko it's easy to see that a lean dosing program can produce exxcellent result - but not at the speed of a high tech tank. It's simply not possible.
Barr independently tested Powersand, which is just Pumice. his results show that Powersand is packed with nutrients, but that due to the high porosity, the nutrient load dissipates within a matter of weeks. Other than the nutrient boost there is no demonstrable evidence that Pumice is any better of a biological filter substrate than any other porous clay. If that was the purpose then you should be able to use activated carbon or sintered glass media as a substrate with superior results, because these materials have orders of magnitude more surface area than pumice.
Additionally, the method of soil oxidation is a direct function of the plants. How do we assume that oxygen gets to the substrate? Because of pumice? How about the fact that plants produce oxygen in the leaves and that they send oxygen to the roots, which then disperses the oxygen into the substrate thereby feeding the aerobic bacteria. I don't use pumice and I've never had compacted sediment. Any clay sediment will be fine.
If you think that the explanation given is true - or even if you think it's just marketing, then the best way to be sure is to actually go and test this yourself. It's easy to do. You don't need a large exotic scape, a couple of small nanos will do. Setup the tanks with everything identical except that in one tank use the suggested Powersand. In a third tank, use some other material such as activated carbon, Zeolite or sintered media in place of the Powersand. Check the results over time and see what the differences are.
You know, in the past, for years, people were told about the benefits of undergravel heating cables, how it was vital for flow in the substrate to avoid compaction and anaerobic areas. When challenged, it was discovered that there was zero benefit to heating cables. I also remember how Latterite clay was supposed to be THE substrate for plants because of it's Iron content and how plants needed soft water, how special "plant bulbs" were necessary for optimum growth. In the end, we discovered that these were all marketing ploys. Veterans of the psychic wars are immune to modern day marketing hype. The only defense we have against the barrage of marketing hype is our knowledge of the truth and our experience. We had to learn it the hard way.
Again, we're not saying that any of this stuff is necessarily bad, just that they are not as important as other things. So the idea is to figure out what things are important and to concentrate on those while ignoring the things that don't make much of a difference. So if you can afford Zimbabwean Sand and Powersand, then sure, go for it. They won't hurt, but you had better be keenly aware of the nutrient requirements of your tank within the context of your lighting, flow and CO2. Then make the adjustments from there.
Also, have a look at JamesC's
UG - Utricularia graminifolia grown with nothing but clay substrate and which many others using mega price substrate often have difficulties...
Cheers,
