Did the major reorganizing in the tank, cleaned the walls, upgrade the filter to AquaClear. From SeaChem: Prime (1/2 ml to 4G) and Excel (2ml to 4G) and as per your recommendation very little baking soda to bring kH up. And here is the result:
NH3/NH4 - 0 ppm
kH - 3 - 35.8ppm > I think it's more 4
gH - 4 - 71.6ppm
pH - 7.1
T - 75°

Will see how the algae will do ...
Can I add CO2 now? Or I should wait and see how Excel will work first

PS Man, that Excel smells ... but it's manageable ;)