To be honest, CO2 tablets are just a waste of money.
They do not provide a steady supply of CO2, and in the short time that they are producing CO2, most of it is not even dissolving into the water column, making them useless.
If you are only planning to add the CO2 tablets once a week, you might as well not add it in the first place. The "trace elements" that are included with this new product you found is probably harmless as well (likely the amounts are so small that overdosing is next to impossible).
You would be better off just using Excel.