rom my perspective 5.3 K is plenty for a weekly dose, we can adjust this if someone really want to add more. This dosing can be used in low or high tech setups just like EI style dosing. It is my advice to maintain lower PH less than 7.0 just to be safe while using a fertilizer that usually contain Urea or NH4. I use to dose Urea in PH above 7.0 water without any issue, but with extra precaution.
The recipe below is based on 50-gallon (189.27 liter) aquarium and you can adjust the dosing to your own tank if needed.
500 ml solution, 20 ml per 50 gallon
Step #1
start with 450 ml Distilled water
Step #2
Add 0.25 gram potassium sorbate and mix till fully dissolve
Step #3 (Pick one from the list below, White Vinegar is Preferred) and mix till fully dissolve
Add 0.25 gram sodium benzoate
Add 0.5 gram Ascorbic acid
Add 5-10 ml White Vinegar
Step #4
Add 31.545 gram Solufeed 2:1:4 and mix till fully dissolve
Add 5.721 gram Solufeed Sodium Free TEC and mix till fully dissolve
Step #5
after mixing all the chemicals, add distilled water to reach the 500 ml solution
20 ml per 50 gallon (189.3 Liter) dose will add the following:
N 1 (Urea-N 0.466 ppm, NO3-N 0.54 ppm) this adds about 2.4 ppm NO3, Rest of the N is from Urea
P 0.2
K 1.766
Fe 0.11166
Mn 0.02818
Cu 0.003446
B 0.0125
Zn 0.019
Mo 0.002146
Mg 0.1266
EI style 3x a week dose:
N 3 (1.4 Urea-N, 1.62 NO3-N) this will add 7.18 ppm NO3, Rest of the N from Urea
P 0.6
K 5.3
Fe 0.335
Mn 0.08454
Cu 0.01
B 0.0375
Zn 0.057
Mo 0.006438
Mg 0.38