Personally I'm confused... why are you adding the aragonite? I thought it was a substrate. it has buffering abilities but I don't beleive that they wear off...
Anyway, maybe if you tell us what you are using it for, maybe someone can tell you better.
i was just curious with cleaning and it being sucked out while cleaning the sand and it comes out while doing water changes if i can add more back . sorry if confusing.
casey
the only problem I could see with adding more would be the time it takes to seed the new. you also would be covering things on the top layer of your substrate, but if you do this with only small amounts it shouldn't hurt...