Absolutely worth a try and much better on the pocket book also.
There are many people who dose this way, or similar. It is not necessary to buy that all in one additive that cost a hundred times more to purchase then what you have listed above.
Read and enjoy, make sure you have a good reliable test kit, ie salifert or seachem
Jim
edit: I purchased from these guys when they were called two part solutions.
Bulk Reef Supply - Bulk Reef Supply