It's worked very well for many.
Lacking much knowledge about other systems than my own, I'm content to work with my own and chip away at each component.
So when someone asks if excess PO4 causes algae, I know that it cannot be that at least.
When you add dual phases, you cannot tell how much of the CO2 enters as gas or a liquid. All you can do is measure indirectly with O2 evolution and measure the aqueous CO2ppms. You assume that the rest of the increase in pearling/growth is due to the gas phase.
That does not tell you what about the gas phase causes the growth increase though.
It could be the breaking up of the boundary layers better etc, or more CO2 gets to the plant faster, more is transferred via the gas phase across a diffusion layer etc.
But as to the effectiveness, it seems pretty clear to me that 20-40% more growth is certainly a good thing. It also can solve some nagging issues for folks with chronic algae or other CO2 related problems.
Many that have assumed their CO2 was okay are surprised to see the difference.
If you where not limiting CO2 and had good nutrients, then you would not see nearly the same impact, but still some.
The current in the tank and plant species can be variable etc, but the bottom line is that it does work and improves growth.
And not just for a day or two, it keeps the growth high.
Once CO2 is good and stable, then the plants really get cooking and the uptake of NO3 etc gets going.
Paul Krombholz did a study back in 1966 where he found that plant growth dry weight was maximized at 20-80ppm of NO3 for several species of aquatic weeds. 20-30ppm is what I suggest also.
At 5ppm, there was 4.2 less growth, at 10ppm, there was 2.2 times less growth than at 20ppm. This was in Limnological Botany 1975.
There is a lot of support for nutrient rich streams in Europe and in many lakes in the USA that have a high % of plant biomass surface cover.
It's just many folks did not look for such information 30-20 years ago and the books that are out are outdated and quite old, many with misapplied references and not good understanding of the primary research and how to synthesize it to the present issues in this hobby.
Regards,
Tom Barr
Regards,
Tom Barr
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