You (ManWorld42) said in your last post that you have NOT used KNO3

Dec 11th
"I read from
some old postings to use stump remover. The claim was that stump
remover is really KN03. I am actually going to Home Depot to see if I
can find some stump remover. If the label checks out, I am going to
give it a try."

Then you said on Dec12, one day later:

"I don't inject CO2, and adding N significantly improved growth."

Okay, so how would _you know_ whether it helped or not? In what? One
day? What other sources of N are you using then?
Amusing that you leave certain things out and that dosing N is
significant but you have no experience with dosing it.
You made NO mention of any other source of N source other than KNO3.

That plus the other snide comments sounds like you are a Troll, not
anyone that is trying to help dWhite.

Limitation (say NO3 vs CO2) can switch back and forth depending on
conditions. We have no info on the NO3 levels or fish on your or
dWhite's tank.

In terrestrial agriculture, the CO2 diffuses 10,000 times faster than
in aquatic systems. So N and P are the main limiting factors there on
land, not CO2. In aquatic system with high macrophyte growth, CO2
becomes very limiting due to slow diffusion of CO2. Search "Limnology
and CO2". See www.thekrib.com as well for more discussion on CO2 and
the issue of diffusion.

I am far from, as you say, "totally wrong":-)
It is clear you do not have much experience with nutrients nor dosing.

You have not used KNO3, I've been using it for over a decade.
Non CO2 does not mean NO CO2, it means it is present at low levels and
is reduced during the day time by the plant uptake.

Generally folks that have poor plant growth and want to increase the
growth rates will look at the CO2, it is the lion's share of plant
biomass(40%+).

That's what this person is asking for(improving growth).

So that would be the best place to start. But they are not really
wanting to get into CO2, SeaChem's Excel is a good alternative as well.
Increased fish feeding will supply enough Nitrogen for a non CO2 tank.
The poster also has course gravel. I suggested to change that if
possible.

Your tank may very well be N limited and not CO2 limited.
But for most tanks, that is not the case. Most folks have more than
enough N from fish waste and feedings, tanks with high plant biomass,
easy to grow plants, low fish loads may very well be N limited. Adding
KNO3 to these tanks will siginifcantly improve growth.
Adding CO2 will help more generally for most folk's tanks as rule
though.

Non CO2 methods are for folks that generally want less maintenance,
less growth etc..

Adding fish food is easier than KNO3.
Having a good substrate will also going to go along way to improve the
growth/cycle the fish waste.

BTW, you can add PO4 to a densely planted tank and get more Plants, not
algae. This is true for high plant density subtropical shallow lakes.
Adding more PO4 or NO3 only produced more plant biomass, not algae. The
study was done on 319 lakes in Florida.(see Bachmann et al 2002).
That's a lot of lakes with plants.

My PO4 levels are 1 to 2ppm as measured by Lamotte and Hach test kits
and compared against standards, I have not had algae issues for
decades. So if that is true, where is my algae?

I do not recommend PO4 dosing for non CO2 tank unless you have no fish
or very light fish loads and it's simply easier to add more fish and/or
more fish food to make up for the N and P.

At another point, the tank will get to the point where the N and P will
be non limiting and then the CO2 will be the limiting factor.

This is why you might be lead to conclude that the tank you have is N
limited and likely was.

Still, if the tank is mostly CO2 limited, adding KNO3 would be the next
best thing to add, I'd suggest fish and fish food though for a non CO2
plant tank.

Certainly much easier.

Regards,
Tom Barr