PPS pro works at 15ppm for exact SAME REASON as does PMDD.

As a matter of fact, it darn neat the same advice and target paremeters.
Hardly new, hardly advanced and hardly the method that drives better plant growth.

ADA uses a similar routine for the water column, but drives plant growth far better by using more CO2 and as a large amount of nutrient via the sediment(ADa As etc).

If you limit PO4, which is a decent nutrient to chose if you had to pick one, that will reduce the uptake of everything up stream from there.

It does not however, limit algae.
Plenty of folks have a lot of algae related issues, same with any method.

If you strongly limit PO4, you also limit NO3 uptake, as well as NH4, and certainly less CO2.

And you can use less light obviously.

However, this is a much smaller target that using less light to begin with, then using that to control rates of growth. Both myself and ADA have long used that advice (going back at least a decade).

Take a look at PMDD advice.
It's virtually the same as PMDD.

Here's the link and it's been used since 1995. Much longer and without the new name and new claims that it's someone else's and that they developed it themselves.

Practical PMDD Information

and

Control of Algae in Planted Aquaria

That's pretty much an out right lie and claiming your work is really someone else's.

I came along and used non limiting growth as a standard rather than several factors which could vary and make comparing anything nearly impossible.

Basic science suggest you need a standard reference control for non limiting growth if you want to compare different limiting treatments.

However, such logic eludes many.

If you limit light, which Sears did, and I've had these same talks with Paul over a decade ago and debates, you have less demand.

2 w/gal of plain old FL's was about anyone had back then. I used MH's and Fl's as well on other tanks.

I needed 30ppm of cO2.
I also needed higher levels of nutrients.
I had not sediment ferts at all.

I also found that nutrients did not limit algae, which is why I kept adding them to see if I could induce algae.

Still to date I never have with PO4 or NO3.

However, you can certainly limit plant growth using light, CO2 or nutrients,.

That is common sense.
Choosing PO4 is hardly something new, and when you have less CO2 because of a PO4 limitation, you obviously have less CO2 demand as well.

If you want slower plant growth, go non CO2, then no dosing , no water changes and no CO2 issues
Method works far better than EI or PMDD.
It also tends to use less light.

How far do you take such logic?

I explore the entire range, not just one side and put poor assumptions into my model merely because I believe it and can make is sound all nice and furry.

If you plan on dosing plants and want leaner or reduced dosing for some reason, say less plant growth, start at the non limiting range(ei) then reduce it down slowly.

Do not start at the supper lean end where the potential for stunting plants and algae are higher.

Use less, not more light.

Use less, not more CO2(unless there are no fish etc).

These things are common sense, but folks muddle and confuse such basic things and inject their belief and uncontrolled observations and algae blooms.

Adding 3-4 way interactions are almost impossible to find anything significant, let alone single factors for most aquairist.

I can do 2 way, but have not tried any 3 way, they get geometrically large at that point. Does not matter too much at 3 also, you tend to bounce between 2 limiting factors, very rarely a 3 way issue.

Regards,
Tom Barr