After a 50% water change should I be dosing with minerals and nutrients?
Yes, add prime for volume of WC then add your ferts.
I’ve TNC complete is that good enough?
Yes and NO
its does contain
1.5% N, 0.2% P, 5% K, 0.8% Mg, 0.08% Fe, 0.018% Mn, 0.002% Cu, 0.01% B, 0.01% Zn, 0.001% Mo, EDTA
which should be plenty for a low tech tank (no CO2 injection) but if using CO2 injection much will depend on your lights, if your lights are powerful this will drive plant growth and you will need to increase your dose of TNC accordingly.
But remember TNC complete is basically just water with a few ionic elements/compounds in solution so soon gets expensive.
Going down the EI fert regime and making your own ferts saves lots and will improve on the ferts you supply the plants at the same time.
Noticed Green Aqua use ADA Brighty K and Minerals.
Yes and great results but they get there ferts at cost and they sell them
. ADA ferts are well expensive for the ferts they give and you can easily do a simualer fert mix DIY at a mega fraction of the cost of the ADA one.
Plants dont care about brand as long as they get the fert