40% daily water change with what kind or water?Tap or RO or?
Most tap has some NO3, some has PO4 like my old tap water here in Marin.
The dutch did large frequent water changes and had high NO3/PO4 in their tap. Many places have this.
The issue for me is the moss, it does not have roots. So it's getting enough nutrients.
And if it's able to grow, so is algae.
I've found algae in places where we could not measure any NO3 or PO4.
I just do not buy folks saying algae can be limited while the plants are not.
I've never found evidence of this in the research either and I have looked.
Algae phyisology just does not work that way.
Plants will grow in those same places also, but the substrate is the source.
Many waters have a pH of 5 and no measurable hardness/nutrient levels.
The other issue is that the nutrients are often used up as fast as they leech so you really do NOT know how much of the jobes is going into the water column or is available for either plant of algae.
Plants also leak a fairly substantial amount of nutrients.
Both Tropica and Amano have done small tanks like this with no substrate and water column dosing and daily changes.
If you are going to go to the effort of a daily water change, dosing is not hassle.
As far as elements causing algae, this is fairly clear.
But I will challenge you to show evidence that you can limit algae by nutrient limitation to the water column and still have healthy plant growth.
I can clearly grow plants with zero algae with high nutrients, so does the nutrient levels in the water help?
You seem to assume that they do.
That was my point.
We can find many examples I nature of this situation, but it does mean it's preferred by the plants nor limits algae in any way.
That is a dangerous assumption.
Plants have a source of nutrients, whether from the substrate or the water column, they will do well.
You will get higher growth rates, thus preference with the water column.
It's not an issue of MY method vs a substrate method, that has nothing to do with it. I'm making a point you gain nothing by doing such a method dealing with algae.
If you dosed back the KNO3/KH2PO4 and did daily water changes etc, the plants would grow great also without any substrate and there'd be no algae. I've done that also for close to 10 years. I also tried the rich substrate approach, we have archives and archives of this on the APD, we went around and around with it there.
This is nothing new.
Not sure why people think it is, sort of ironic.
I did that substrate water column clean method also.
One thing that helps the water column clean method today is huge water changes and higher CO2 than in the past.
This seems to have a negative effect on the algae spores(water changes) relative to the larger plants which can take the shock better.
It's not so much the method, it's the large water changes daily.
Using TDS is not necessarily going to tell you your NO3 level at all.
If you are using CO2 and have that measurement, then you must have a KH and therefore some TDS, likewise for GH to some degree.
Try adding a small amount of a stock solution of KNO3 to see.
The small trace amounts of PO4/NO3 in the tap water are not going to show up. Unless you are using reconsituted RO etc and have measured the tap with a good quality NO3 kits, it could very well be the case.
Folks use to say I had "magic tap water".
There's no magic and because I am being critical and looking into this question it does not mean I am being anything more than that.
These are valid issues that sometimes cannot be addressed directly so finding other ways to solve the problem or question is sometimes needed.
I'm not partial to a method, I'm partial to an understanding without so many assumptions.
This is how you figure stuff out.
That's the goal, merely saying there is another way than my so called way(which I there are many ways that I do and have done things including this one... ahem) is not going to solve or help better understand things.
Methods need to be looked at critically, not just bashing the critics or another method, that behavior is politics, not science.
A cat can only be skinned a few different basic ways, but there is more than one