I question the methods used to obtain such test data.
They are not testing where the nutrients are either.
What the heck.
Temporal and spatial issues are confusing many hobbyists that are simply unaware that you can have several locations for nutrients in an aquatic system, they all work and the rate of growth is also a defining factor as well.
In a nut shell, plants will and do grow well with nutrients, they need to a sufficent supply based on the driving growth rate, this starts with light, then CO2 and NO3/K and so ion down the line.
You can deliver them via roots and/or leaves or both locations.
There is no conflict with any growth model by having them in one location or the other, just that they are present.
At higher light(such as natural systems), you will place more demand for this and adding the nutrients to both locations should yield the highest growth as shown in terrestrial systems as well as aquatic ones.
Amano and Dupla and many others have made claims that anything other than low water column nutrients for N and P = algae blooms when it excess.
Perhaps this is a hold over from fish only aquarium keeping.
Clearly they never tested their own hypothesis on this, adding these accordingly should induce algae, but that has not been observed in well over 15 years. Yet they continue to make such claims while quietly adding NO3/PO4 for some cases in recent years.........
Test methods are very poor, I see no methods list.
Sounds like they had some conclusions and then went about looking for data to support them rather than testing them.
They also did not test the nutrients where they count in these methods: in the sediments. C Kasslemann gave a long presentation about the water column nutrient levels/parameters for swords plants in natural systems.
She suggested that these plants do not prefer water column nutrients and that they live in oligotrophic environments. I asked her if she had measured any pore water of sediments in all of her studies and field trips as is basic protocol for wetland ecology. Her answer: "no".
Asked what was in powersand Amano said "power".
This means they do not know or have and are not telling anyone about it.
In both cases, that leads me not to trust them.
Neither have done any algal studies.
So I'm not sure what their logic is for low water column nutrients as being some sort of advantage nor have they offered any explanations to date that remotely match observations.
There are several methods available for sediment measurements for wetland soils for N and P.
My main issue is seeing how well the plants grow in a soil vs ADA AS condition and with respect to the water column.
How can we fairly judge the water column under a wide range of limiting conditions? I do not think you can. I think that we have to have a standard
control here for the water column.
CO2
K+
Ca
Mg
B
etc
Are all water column nutrients, folks add Traces all the time as well.
The resolution to show limitation of algae is beyond the best hobbyists kit for N and P. The nutrients are taken up so fast that testing the water column will tell you nothing. Yet the water column often is only determinant basis for dosing programs for many aquarists ironically.
ADA does not suggest extensive measurements in their routines, "watch the plants and add just enough".
Using acid extraction to measure plant bioavailable P and N are commonly used in horticulture of sediments to determine relative fertility.
ADA's data numbers also just do not add up using things like the KH and pH and CO2.
I can see an over estimation of CO2 occurring, but not under estimations.
That's so improbable I have to serious question such data and when such measures where taken.
I started off doing very well in this hobby with the water column without knowing "why". I could have stayed on that path and spent my time scaping more. Jeff really does not care nor Amano nears as I can tell about why, just that what they do works and allows them to scape and do a nice tank.
Jeff freely fesses to that and Amano sure gave that impression both times he was here in the USA
I'm concerned about a larger management issues in aquatic horticulture.
The why is very important in understanding and development of even better methods to grow plants, how to address a much wider ranges of issues.
Unlike many, I have many methods that I use to grow plants, and this allows me to compare each methods' trade off/s and focus on the best management for a particular goal.
There are many folks in this hobby with many goals, trying to bully folks into one method is ethically bad and wrong. Further, no single method will be right for everyone's goal. I commonly suggest and support non CO2 methods, Excel methods, marine systems, EI methods, test method suggestions, substrate water column issues etc, algae control, tap vs RO etc.
Some clowns have accused me of bullying folks into a single method etc, but if they look at the management issues, what's the best cheapest and gives the best results, I fully support my contentions there. If the clowns cannot, then they shall remain clowns.
Clown theory
I've changed my advice as I learn more. Many never do sadly.
They go back and instead of rejecting their old falsified hypothesis, they run around looking for data to support their conclusion.
Ted showed some serious doubts about the gas in a CO2 reactor that I had made a hypothesis about, I still do not know what it is, but I'll be finding out soon (Gas analysis here is now available in a friend's lab, but I'll have to break out the Reactors and collectors again, but I have growth chambers at the lab now, so that will be a lot easier).
But it's not about pride, it's about figuring out what is going on and why.
Make lots of hypothesis and then try and prove them wrong. If they are, let them go and move on to the next and try and get to the bottom of the issue.
Do not hold on to them so personally and be ego driven.
Be curious as heck and doubtful of yourself.
Regards,
Tom Barr
Regards,
Tom Barr
Regards,
Tom Barr