It depends on the dosing method.
I'd say it depends more on the people involved.
Every single dosing method around has examples of true failure and algae.
It's not the method of dosing, that's only 20% at most, it's people that fail, not the method.
EI or ADA are not the only working method.
How about PMDD and non CO2? How about sediment ferts?
You have to add the same things no matter what, so the methods are not that different.
Plants grow for the same old reasons after all............
EI is not that different from PMDD, it added more PO4 and pretty much everything nutrient wise(and CO2 and light). PMDD is leaner, but adding less EI is nearly the same thing.
Non CO2 can go either way, this is very much like your view with respect to dosing the water column and avoids all water changes for the most part.
I suggested a method to do a non CO2 tank with no sediment based ferts.
However, just like the CO2 enriched methods, adding them and water column ferts provides the most stable long tern solution.
The rates of growth are different, due to less light/CO2, but the methods are pretty much the same, they add the same things, and in different locations.
They used Hoalgand's solution for hydroponics and for the study above.
EI is pretty much like that, it's a non limiting amount.
Then you reduce it down slowly, till you see a negative response.
You do not start super lean, then raise things up. Research and Science are not done that way, you have issues with very lean because of limitations and confounding factors influencing results. If you start at non limiting levels(sediment and/or water column), then you can be assured of independent results.
You can reduce and lower one nutrient at a time(I've done this many times) and test what effect it has on algae, plants, a particular species etc. This way you knwo that the other nutrients, CO2, light etc is not influencing your results.
This way you learn much more about the plants, and that nutrient's effect.
Note, you do not need a test kit to do this either, you can eyeball it with plants as the test kit (hint).
This is how I figured a particular Trace dosing rate that was non limiting.
You can have a beautiful high light tank without big water change and by dosing accordingly to plants needs (that's to say not 3x what the plants may need).
I've never said it cannot be done, only that given many of the trade offs, human, labor, watching their tanks when they are away, busy with other issues, cannot get them to test, or watch the plants carefully..............
If you want to whip a tank into nice shape for a photo shoot, I would certainly suggest doing 2-3 water changes per week and stay on top of everything.
"Need" is ambiguous.
I do not "need" CO2 enrichment 10x more than the plants "need" for example.
You cannot play this both ways, or add more light than the plants need.
You go with a "lean" concept, stick with it for the light and CO2 as well, since they play the dominate role with any dosing methods or concentration.
Why go lean with the last part of what provides plant growth(nutrients), when CO2 and light are both high?
Why waste all the CO2/light for lean nutrients?
This is not a natural system we are doing here, and we cannot control light/CO2 in natural systems, we can control nutrients much more. So that's why we see a lot of talk there and "nature", but adding CO2/light are options we have as aquarist, as an environmental manager, they do not have such options.
So we have the choice to start where all plant growth begins, light and then CO2/or not.
From Bjorn Hoorelbeke. High light tank. No flourite, no ADA AS, just a layer of plant substrate under the gravel. weekly 25% water change.
And this adds what?
what is plant substrate?
What's in the tap water?
What else do they dose?
These are basic questions.
Let retouch the cherry red colors that have been photo shopped also:
You suggest "I could have a very easy to care for by reducing the light and it would be easier to maintain."
That's perfectly true and a good piece of advice. What you forget to say is that reducing the light can also have some unwanted effects.
Such as what unwanted effects??
I'd be careful with this one, all I need to do is show an example of nice Tonia, any no# of red plants with lower light............which I have.
If some ambiguous "unwanted effects" is all you have..........be specific and see if you can falsify those so called "unwanted effects". What specifically are speaking of there?
This is the main thesis for your argument here as well as reducing water changes(which is a non issue, I have no issue with anyone doing this and suggest it in EI and various other methods I've mentioned over the years).
If there was absolutely no advantage to have 3W/gal instead of say 1.5W/gal, everyone would use 1.5W/gal.
This is simply not a logical statement.
Plenty of folks believe more light is better and have long been marketed by light companies, magazines and LFS's.........this has gone on for decades.
Name some plants I cannot grow at this level of light, say 100 micrmol/m^2/sec.
This is about where the light was on the tank I showed, and I know the tank, I know the person that tends it and see it in person, the picture I offer are not clips off the web(James ADA tank is the exception, but I spoke with him in person)
This is not because some Rotala sp green, java fern and eleo parvula do well with 1.5W/gal that every plants will show their best with that lighting. That's not true. Like I said prior it depends on which plant you are considering. Tonina and java fern have not the same needs (not in quality but in quantity).
Plenty of folks have nice Tonia at these same light values I showed above
Tonia is a weed.
But of course you can have beautiful tank with low lighting setup, never said you couldn't. Just have to pick the right plants.
Such as what? Beside Tonia?
I already can tell you folks grow it nicely without higher light, 2w/gal or less(cut off for high to med light).
I think we are bit closer on things than you might, and myself at times, realize.
However, try and see if you can disprove your own claims
See if you can grow certain species like R macrandra, Tonia, various stem plants, L pantanal, Gloss, HC, foreground plants, red plants etc nicely at lower light.
I think you will be surprised.
At lower light, they do better than most thing and have long been led to believe.
Try a light limited tank where you have plenty of nutrients and plenty of CO2, this gives optimal light use efficiency.
A concept I got from Daniel when discussing PAR vs PUF. Also, read Tropica's research with light and CO2 with Riccia.
I think you will find tweaking dosing is rather easy, light is very interesting and CO2 is the hardest of the 3.
I have a data logging controller that is planned for CO2 using partial pressures, no issues with pH, KH or water chemistry, just dissolved CO2.
I'm not sure how CO2 mist in the gas phase affects things
But that's another topic, but I'm excited to play around with some control functions and have an accurate meter ( about 1ppm).
Light meters are also useful and good for folks who do not like to test, they are quick and easy to use and then you do not need it for a long time after.
Makes comparing light between tanks much easier, simpler.
Hope this helps.