I can get most of the elements from a company that sells water fertilizers (please check the link and tell me if that is what I need):
I'll try to get a Seachem Equilibrium from USA too, once again will adding only KNO3 and KH2PO4 + http://www.pfertz.com/rootferts.html
have positive impact on the plants or that will mean a problem (algae)?
Tom Barr non CO2 method
I added once a week KNO3/KH2PO4. While trace mixes can be added, I decided to use SeaChem Equilibrium instead. It has Fe and Mn as well as Ca/K/Mg/SO4. I will add about 1/4 teaspoon per 20 gal tank once every week or two.
This greatly enhances the growth of the plants. I also will add about 1/8" and 1/32" teaspoon of KNO3 and KH2PO4 respectively once a week or two. Note, GH Booster can be used instead of Seachem Equilibrium