This phrase deserves a separate thread.


And WHAT you test. Plans do use DOC (amino acids etc) and other organics from water column and sediments. In ocean there is a 5-6ppm of DOC, in rivers much more.
How much Fe bonded by organics in sediments and in water column etc. ?
Never seen such a data on rivers in those “scientific” books on planted aquaria… Never.

Moreover, our plants grow mostly in rivers, but there is a FLOW.
Take those 0.05-0.01ppm of PO4 which most of folks consider as very lean nutrition, and multiply by slowest river flow 0.5m/sec – you will see that plants during light time have unlimited source of P…
Water/plants mass ratio is much more in rivers than in a tank, so PO4 source replenished at any moment without problems. Day and night. It NEVER comes to 0.000ppm.

The same thing happens with “low” supply of CO2~5-10ppm, NO3~1-5ppm etc.

I have never saw people posing such question to themselves…

This is the same as to change ALL aquarium water every second(!) with those lean 0.05ppm.
How much PO4 will pass along plants leaves during a day? Ha!?

Comparing to this, “high” EI dosages is a mere TOY :-)

Place a plastic box from water surface to the ground around lush batch of plants in a river, and I am sure soon they will stagnate.

This is why we should dose in a tank much more, and it does not leading to algae – it feeds our plants which out compete algae.

One more thing which surprises me quite well is misunderstanding of terms “dosage” and “to keep level” in a water column.
You can dose 5ppm of PO4, but when plants grow well, concentration in a water will be, and must be, very low (say PO4<0.2-0.1) quite fast. No?
Maybe Tom made tests on it?
Or I am wrong here?

naman