Well, plants are fairly adaptable, so they can respond nicely in non limiting ranges and also in limiting cases also.
the question is really what method has a high % of success, simple, easy to do etc, vs another? This might works for 80 people but not 20, and those 20 will complain a lot. For whatever reason, they cannot get good reds or algae issues, something.
There's many ways to go wrong and this includes limiting N strongly also.
Limiting P is much safer actually.
Or limit light etc.....
Or chose a species./variety that is naturally red independent of environmental conditions, the L perunesis or the Red rubin types fit this nicely.
Some add lots of lighting.
Some use rich sediment and then not much in the water column, but this runs into issues after the sediments are exhausted.
I suggested limiting N to reduce the Chl a in the tissue that mask the red pigments back around the mid 1990's.
But there's a fine line between nice red color and stunted red plants.
This is a bit tricky and works well when you dose daily and fuss and manage the N real well, or have slower growth rates due to other factors beside just low N. This tends to set you up for some sort of issue when you slip up.
Some can do it, but IME/IMO, this is about 5% of folks, maybe less. But those 5% scream like a cat who's tail just got stomped.
If the limiting N is the key, then if I can dose as much as I like and still get good nice colors....then this sort of blows up the entire argument.
I've logn stated that folks that fuss and tweak and pay a lot of attention vs not.........often will have better results.........but this may have nothing to do with the ferts and you cannot says that the ferts caused X, Y and Z..........without running the risk of that hypothesis being falsified.
There are many labor intensive things that work, or special skills, magic powders, but what good are they if few will/can do them???
Not much.
