Lately I've been reading more that the high grade carbons for marine tanks remove "trace amounts of trace elements but not enough to disrupt the chemistry of the tank."
That aside, you need to weigh the benefits and drawbacks of it and make the decision for yourself. If it's to improve good conditions and make them better, then go for it and watch the inhabitants of the tank for any changes in behaviour. If it is to fix bad management practices, then those need to be addressed directly. In that case carbon is only a temporary fix, not a long term solution.