One of the issues with blanket dosing regimens is that each tank is different. I think a library/compendium of people's stocking levels, lighting levels, substrate/substrate fertilization, CO2 additions (Y/N), and regimen would really help us to understand what to do about fertilizing.
Information should be like this:
# of Small Fish :
# of Large fish (above 4"):
Lighting type & wattage:
Distance from top of tank & photoperiod:
Known Algal problems:
I know it's a lot to ask for but I believe it'd be very helpful for the hobby and for people looking to set up new tanks. Being able to just skim through a thread for settings similar to their own would make life wonderfully easier.
Tank Volume: 17.6 gallons
Substrate Type: Fluval stratum
Sub. Fertilization: Osmocote +
# of Small Fish :10
# of Large fish (above 4"): 0
Lighting type & wattage: ~36watt T5HO
Distance from top of tank & photoperiod: 5 inches above tank, split 2 on 2 off 4 on
Co2 Addition: Yes
Fertilization regimen: EI as per tom barr, no N added, Daily dosed via liquid
Filtration: Fluval 305
Known Algal problems: Green dust, bba, green spot
Known Deficiencies: None.
Plants (Optional): L. arcuata, L. brevipes, B. japonica, E. Acicularis, S. 'porto velho', R. mexicanas goias, H. verticillata., purple bamboo.
As for why I have no N? It's because my fish/osmocote are making up for it. I'm hovering a constant 50ppm Nitrates without adding N. I believe strongly that bioload has a lot to do with what's happening in addition to the osmocote. So just in case there's some wild card I'm forgetting it may be important to know what fish are around.
I think for new folks, they want to KNOW what to do to care for their tank well and not make mistakes.
As with anything NEW, there is an insecurity and a sharp learning curve. Information overload is typically a problem, thus simplifying things for them and getting them to consider the big pictures, eg LIGHT and CO2 are much more the key.
Fertilizers are way way down the line for a newbie or the advanced aquarist interested in plants.
Light and CO2 are much more what defines the rates and the different methods.
Measuring sediments is not done by hobbyist, some comparing those is rather difficult and their nutrient content can vary wildly over time and age, but plenty of hobbyist use that source.
How can you account for that?
I do not think we can easily.
I think it's wiser for the newbies to look at this article:
See table 1. You have nearly 20X difference in growth rates on that table which covers most of the ranges folks might use for light and CO2.
Plants GROW in ALL cases, but the RATE of growth changes.
Without taking into account these differences, a factor of 20X is going to place a massive difference on adding nutrients and what is the best management. You will note, in Troels and Ole's study, they used a non limiting nutrient solution
, this made CO2 and light independent so they could explore CO2 and light. EI does the same thing
I do not think piece mealing ferts is a good idea. Measuring CO2 and light are two large issues for newbies. Folks spend way too much time and energy on ferts from my view. Not enough on CO2 and typically add too much light for their stated goals.
My variables on your list above vary about 20-30X between the tanks I have at my house.