[plantbrain]

Well you likely have soft tap water in NY, so Ca(NO3)2 would work just dandy and add some MgSO4 baking soda and that would take care of a lot for you fast.

Calcium nitrate has been used by a few folks mainly for the Ca and the ease of getting it to dissolve vs CaCO3.

I know of no upper limit on Ca levels, I've been to 440ppm.
As far as K+, I went well above 50ppm recently. Erik said he went to 100ppm K and we both grow Ammannia and funny odd plants etc.
I know the high K+ thing is a bandwagon, but whatever works as long as the K+ is not limiting.

Using KNO3 alone is enough to take care of both needs though so this upper range in the 30ppm or higher is not needed but it will not hurt, if it was as bad as some folks say, folks would have been itching and complaining for the last 10 years or so.

So some said it was with only certain plants, well, I have those plants.
I grow them just fine. I added more K+ a few weeks to see if it occurred like these folks said.

No change for me. I have not observed anyone's high K+ exhibiting these symtoms in person, nor my own over many years. The K+ is there, all the other things needed for good plant growth, but I don't get the stunting.

I have found nothing in the research either suggesting this in aquatic plants.

Regards,
Tom Barr

 

[plantbrain]

Perhaps more traces(and not just Fe) and when you add the NO3, PO4, K+, even GH, this puts a larger demand on the traces.

Still, folks would have seen this more before this. But few folks had ES back then, now everyone has it.

It grows well for me, at 20ppm but I have not tried high K+ on it but I know many that have. It's a funny plant but some of the nicer looking plants have been raised in higher K+ levels.

My advice would be to add more NO3, more traces, maybe some Ca/Mg and then see if the high K+ has much effect.
I suspect it will not.

I think some folks have not been keeping some other nutrients, parameter etc in line.

Some approach things conservatively, too much, or some go the other way and over dose.
Some mix these two together.

Some things are not talked about such as flow rates, plant biomass, filter size, and other non Nutrient issues and this can account for some variability.

I don't know what those folks are doing, but I know what I am doing and what the tanks I've seen in person exhibit.

But this is neither here nor there, I'm mildly interested if it was a real effect I could duplicate, but it's not, so I'm less inclined to do much further work on it after trying the Ammannia out here recently.

So if folks simply add KNO3 and not add any K2SO4 unless they are getting a lot NO3 from the tap or the fish load/low light etc, then
KNO3 by itself for most of the folks with issues should have no problems.

Main thing is to have some excess K, 10ppm is excess K relative to NO3 at 10ppm.

Ratio may help some but the main issue is keeping these nuitrients from becoming limiting. We dose and do water changes often so th3is ratio does not really mean much until things get down low and become limiting or if you try and run your tank very lean, not a good idea IME/IMO.

Some folks might try to add 3ppm daily of NO3/K+ and 0.3ppm of PO4, while I might add 10ppm NO3 every 3 days etc or some might enrich the substrate with something and add less trace, NO3/PO4 etc.

You can skin this cat a number of ways but if things go to zero for long, the plant will suffer.

Adding a bit more and keeping it richer generally helps, NO3 stunting occurs more often than some folks are considering also I believe, especially those that are trying to get more red colors through NO3 limitations.

I and other have been down that road already.

Regards,
Tom Barr