We never suggested adding NH4, at least most don't. That will lead to algae, the pH issue is merely one of toxicity and build up. NH4 will cause algae and that is simply how the fish waste starts off.
Plants typically remove all of it in a well balanced or low fish load. You can have a fairly high fish bioload in a planted tank, but you can also add so many fish that unless you do lots of water changes, you'll get algae every time no many what type of dosing you.
We can also add NH4 inorganically and find the same observation.
But the observation of dosing KNO3 does not produce this result.
If the poster has not added either to a planted tank, then he is speaking out of ignorance and speculation, also...........very unwise.
Try and see, then you'll know.
The poster does not have to prove anything to us, we alrerady know.
Rather, the poster needs to prove it to themselves.
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Bottom line: We already have enough nitrate and phosphate for our plants in our tanks.
Rarely is this the case unless you have low standards.
Even lower light non CO2 tanks can and do benefit from some dosing, of NO3 and PO4, Diana Walstad, myself and a quite a few other folks have added PO4 etc, no algae. She did it with organic forms, fish food etc, at 5ppm of PO4, that's pretty juicy. I added inorganic PO4 to 2 ppm.
I only add it once a week if that. I do not need much there, but still, most fish foods are not balanced forms of plant nutrients, although they do have some, adding a little inorganic PO4, K+, traces, GH on a no water change tank, not enough to allow build up(water changes and test are avoided this way) but enough to relieve the growth limitation for the slow growth rate.
Faster growth, more demand on the NPK inorganic fraction.
Bacteria and plants are not fast enough to remove the NH4 organic forms and process and assimilate it at higher growth rates/light.
So we add a bit more to help.
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According to Liebig's Law, it won't help plant growth if we add further sources of nitrogen or phosphorus.
Actually according to Liebig's law, it proves just the opposite of this poster's intent.
He assumed that the plants are not limited, in extremely few cases, they almost always are unless the owner adds KNO3/KH2PO4/CO2. Even low light tanks are CO2 limited. Adding CO2 allows the hobbyists to have helathy plant growth at lower light levels than without.
You can add it(NPK) to the substrate, you can add it to the water column, you can have it come in from the water changes etc.
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Thus, quality fertilizers should contain trace elements and especially iron
HarleyK
Let me see which plants he can grow and which plants I can grow, as well as his scapes. Why doesn't algae appear in our tanks if this is really true?
Has he tried adding KNO3, KH2PO4 to see if what he claims is true?
We have and have not found this to be the case.
Also, why can we find so many lakes with lots of aquatic weeds, high nutrients, and no algae (the water is gin clear)?
Regards, Tom Barr
most people are glad when they can get rid of them in order to reduce/prevent algae growth. That's why no aquarium fertilizer should contain them. And indeed, I've never heard of pmdd 
Anyhow, NH3 and NH4+ are in a pH-dependent equilibrium. Which means if you add too much NH4+, you will end up poisoning your fish with ammonia. Not a good thing. 
so they take up nh3 what about nh4? and what about nitrites? are they taken up to?
(english is not my language, hoping too learn more though)
