TBF it's a bit difficult to find an answer here. I can only say what I think and maybe point out a few references and such.
Aparently I twist examples, so what I say can be taken as read or ignored
The 1st problem I have is ratio's. They come up every now and then and sink away. They're normally badly interpreted data from the "Redfield ratio" which in itself was flawed also.
IMO a much better way of looking at things is
Liebig's law of the minimum, which basically says as long as you have enough of everything your weeds will be fine - simple - if we then hook that up to the
fact that excess nutrients (Nitrate, Phosphate, Iron etc) don't cause algae everything will be peachy creamy.
The 2nd problem is stuff like walstad and books in
general. The methods may work, and if they do it's important to stick to them. If you deviate from the plan you'll often find yourself in trouble as the "methods" don't work if you go off piste.
They also often contain regurgitated myths like Iron or phosphate causing algae etc.
Get your head round the above and things become clearer. Know that ammonia triggers algae and then try to work out where the ammonia comes from. Use resources like
James' Algae guide to identify algae and understand that it's ammonia causing it...when it says "Low CO2" you know that the low CO2 is causing ammonia (the plant will be dying through lack of co2...
) - If it says fluctuating CO2 you'll be able to imagine a plant leaf trying to adapt to the different levels of CO2, literally changing the make-up of the leaf...frantically slewing off cells maybe - causing ammonia....
If you've got plants that are showing signs of deficiency we can probably guess now where the algae is coming from...maybe even decide that if you concentrate on fixing the plants the algae will be secondary...maybe still a problem, but secondary.
As for target values -
CO2 range 25-35ppm
NO3 range 5-30ppm
K+ range 10-30ppm
PO4 range 1.0-3.0 ppm
Fe 0.2-0.5ppm or higher (?)
GH range 3 degrees or higher
(Tomm Barr)
TL;DR - No i don't have an answer. I wish I could say add this much to that, but I'm not even sure you'd believe me if I did.