Whar is your K concentration now? 16ppm?
I now have all dry ferts (Macros from NilocG) and (Micros from Burr), I was just thinking about what concentrations I was going to try to make my two bottles.
I don't have RODI water so my kH is still around 4 - 5 from tap. 31ppm Ca2+ 8ppm Mg2+ neligible K, Na, PO4 or NO3.
What concenentrations would you use?
I could target 15ppm NO3, 13.5 K+, 5 PO4, 15.5 Mg2+, 31 Ca2+, 0.6 Fe2+ and the other micros similar to you or Burr.
See now this is where it gets confusing sometimes. When you say"K concentration" I assume you mean what's actually in the water column, what I call the target dose.
Right now I am dosing my RO water to have a concentration of 30:10:22 N:P:K. (EI dose 15:5:11). And that's working quite well right now in MY tank. But keep in mind my tank is 100+ PAR, high fish stocking, and lots of stems.
Are you going to keep your PAR in the 50-60 range? Staying with mostly green plants? If so, the numbers you posted above look pretty good to me. My guess is that with your low fish load, you might need to bump up macros a bit across the board, but there is only one way to find out. You probably need less than 0.6 Fe with that dosing, and a little extra Mg never seems to hurt.
Maybe some others with similar PAR numbers could chime in? I would really like to get some data for different styles of tanks, as almost all of ours now are high light/high CO2/stems.
Now if you are going to raise your PAR and start with more colorful stems, that would change things.
More importantly, maintain good consistent CO2, and keep good clean conditions.
I am really looking forward to seeing how things go, and where your tank goes from here.