Many hobbyists want to know what's going on in their tanks. Many hobbyists experience different kinds of problems and ask here (or on other forums) how to solve it.
I think that the best way to solve any problem is to test is under controlled conditions. Let me discuss this in more detail here.
The strength of scientific methods is in the repeatability of the experiments. Not the interpretation of the results but rather the repeatability of the experiment is what has the biggest value. In other words, the experiment is of any value if anybody can repeat it with the same results elsewhere in the world. And on the contrary, the experiment is useless if you can't repeat it with the same results. Not until we understand this, can we move our hobby any further. The biggest problem with our discussions (seeking answers for our questions) is that we base our findings on non-verifiable results.
A few examples:
1) Let's say I make an experiment with growing few aquarium plants under controlled conditions (light intensity of 100 µmol PAR for 10 hours a day, water temperature of 25°C, hardness of 5°dGH, alkalinity of 3°dKH, nutrient content of 35 ppm CO2, 30 ppm NO3, 3 ppm PO4, 20 ppm K, 0.3 ppm Fe, moderate flow, inert substrate, etc.). I'll find out that these plants grow at different growth rates => some grow faster than others. If I describe the methodology (i.e. the exact parameters of this experiment) well enough, anybody elsewhere can do the same experiment and get the same (or very similar) results.
2) Let's say I make the same experiment but I don't know the exact parameters of my setup => I don't know the exact PAR values of my light intensity. I don't know the exact nutrient content of my aquarium water nor the substrate. I don't know what other factors are in play in my tank. So I can't describe the methodology of my experiment. If someone on the other side of the world tries to repeat this experiment, it's highly probable he will get a different results. Why? Because no one knows the exact parameters of the initial experiment.
Now, why do you expect to find any reasonable solution to your problems in your own tank, if we (nor you yourself) know the exact parameters of your aquarium? I think that this is the core problem of most of our discussions. Without first learning the exact parameters and conditions in our tanks, we are doomed to endless speculations. Without the proper methodology and controlled environment we never ever can be sure what's really going on in our tanks.
This is my main objection to Tom Barr also. He makes a lot of conclusions based just on his own speculations. As far as I know, he never did any trully controlled experiment with well documented methodology. So no one can faithfully repeat his results. He uses a clay-based substrate in his main tank, very high CO2 levels, very low pH, very high light levels, quite high flow, big army of algae-eaters, do frequent water changes ... but in fact, we don't know all the parameters which may be in play in his tank. And this is the reason, why his method can't work universally and under all conditions (i.e. with different kinds of substrate, different water parameters, different plant species, different fish etc.). His method works in his tank under the given (fully unknown) conditions. But we don't know what these conditions really are. We know just what he lets us know or what he thinks is important for the success. But that's not trully scientific method. That's nothing more than speculation based on some experience. Until he is able to controll all the variables in his tank, and tell us what variables are at play there and how they affect the whole, we won't be able to repeat the same results elsewhere in the world. We can be lucky and have the same or similar results, but we will never be sure why. It's never a good idea to do any experiments in fully uncontrolled environment like our tanks. And the main problem with T.Barr is that he did all his experiments right in his tank.
Takashi Amano is a similar example although he seems to know better what he's doing. His system is based on the use of concrete materials with concrete parameters. He doesn't let us know the exact methodology behind his system, but if you use his ADA system there's much higher chance you succeed as the crucial parts will be always the same (light intensity; nutrient content in the substrate and water column; filtration capacity, efficiency and flow; CO2 management). You are also recommended to use water with low hardness and alkalinity. If you follow his advice, you can repeat his success elsewhere in the world with much higher probability than with T.Barr's recommendations. Unfortunately, this know-how (hidden methodology) is very pricey. Even in this case we will never be sure why.
So are we doomed to endless speculations or is there any hope in more hobbyist using proper scientific methods?
