This is often the thought process illustrated by a cartoon:
There are many examples..........
K+ causing stunting was a classic one.
Someone found a reference to Ca++ signaling and K+ inhibition.
However, this was molecular communication signaling, not a reduction of growth rate.
When misapplied, not considered in the broader picture, not applied specifically to your specific situation (aquariums with, without CO2, fish, different sediment types etc) many use references. Does not mean they support their claim.
You'll note, we look at facts and see what conclusions we can safely draw from them.
Then we set up a test to see if say, NO3 is stunting these species in our aquariums.
If you have no reference for a control in your experiment, you simply have no idea if that conclusion is or is not correct, all you have is some correlation. You have no way to test if the other factors are independent of the result/s.
You have no way to test or see if there is some other alternative explanation.
That is sloppy and leaves you wide open for making huge mistakes.
This is not inherent in the average hobbyists, folks with PhD's make these same unwitting mistakes.
Paul Sears of the PMDD fame along with Kevin are really smart folks.
However, they did the same thing. They did not test their own hypothesis and check to see if there was some other factor causing algae.
You have to test and check the other alternatives.
Just because you personally came up with inconclusive evidence, does not mean you had everything independent either.
Many aquarist seem to think so. They for whatever reason, make a mistake(but assume they have not) and can not have the same success or are unable to reproduce it, yet many others can, they know they are adding say 20ppm or NO3.
At some point, you must accept you have done something wrong as others are adding it, and not having the same results.
That is a clear sign that there is something other factor you have over looked.
The above reference with P alpinius
may support inert sand+NO3 at high levels in a non CO2 situation, without fish, NH4 or a combo of both NO3+ NH4 is superior for growth...........I do NOT argue that. But generalizing further while ignoring the observations that the rest of the aquarist have(are we all lying?) for the specific cases with.........high NO3, with CO2, with fish, with a wide range of sediments???
Then it becomes another matter entirely.
Then you are being selective with your logic and reference
It has to start with observations from many people, where we can know we have a certain non limiting upper bound for a nutrient. Not just a guess.
That is the control reference to base the test on and the standard that must be applied. Maybe no one has been able to grow A reineckii, A gracilius, or R macrandra in aquariums at higher NO3(No available observations for a control reference). However, for this case, such hypothesis has been falsified already and there's a long history of it.
So it cannot be correct for those species.
Either that, or we are all in a huge conspiratorial lie.
Not likely.
Regards,
Tom Barr