Hummm.......how do you answer multiple methods? :idea:
I think most everyone changes and manipulates things till they realize it's not quite as critical as they think.
Later, they realize light and CO2 are likely the reasons.
I do not dose a thing to a non CO2 planted tank..........other non CO2 tanks without sediment based ferts, I do, but only once every week and certainly at pretty lean levels. But the plants respond well, because CO2/light are limiting, thus growth demand is very low in such tanks.
Other tanks, say at the opposite end, can be driven fast using daily dosing, sediment ferts as well, and high light/high CO2.
Obviously, there are middle ranges of dosing and CO2/light as well.
Keeping these variations in mind can help you see why a so called confounding example works or fails when you try it.
I see folks post about how little they add and things work well, likewise a certain person also used PO4/NO3 remover and had very rich sediment mud. While another had very rich water column dosing. Both worked well.
Why?
Both methods supplied enough nutrients for the CO2/light demands.
However, some assume that one method is "better" as it controls for algae, that's not true.
Algae generally drives folks to try different things with methods, then plant health is next.
I'd suggest plant health as a focus.
Give nutrient routines a fair test also, do not assume that you have good CO2 and light, plant species etc.
Make sure you do before drawing any conclusions.
Otherwise you run into many issues and make bad assumptions.
If you test, test carefully!
Overall, I think a combination of both methods in the water column and in the sediment works best(easy and forgiving) for CO2 enriched systems. Non CO2 system can have any of the 3 combinations and still does pretty well.
Also, be sure to be as critical about fish waste and fish N and P additions as you are about KNO3 measure.
There are methods to measure this.
Regards,
Tom Barr
