I don't know, I've never had to dose this much before - but I've also never had a single tank for this long, or a tank this size, or this many corals either, so I don't really have a bench mark to compare 'normal' against.

However, I have a lot of montipora from at least 4 different species. It grows incredibly fast, and the bigger it gets, the fast it grows. A few of them have super designs skeletons, so sitting here looking at it I can imagine that much calcium carbonate getting laid down all over the place bit by bit every day.