Sometimes such things are necessary, sometimes a simple water change with RO/DI water is all it takes. Sometimes less is more, by that I mean that you need to ask why you might need something like the seachem product, what is happening to cause the nitrates and ammonia to spike for you. Its your system, take a look at how its running, feeding habits, maintainence, cleanup crew..etc.
Hey if you feel you need it and have tested for it then use it, but there are many ways to help with nitrates, explore them.
Thomas