I haven't used it personnally but I used to sell it. From the feedback I have got from it (mind you this was 4 years ago!) it seems like a good product. From what I remember it provides you with the 'essential' trace elements and nothing that isn't 'proven' (for lack of a better word, it is 630 in the morning aha) to be taken up by corals. It doesn't provide Calcium or buffers, so you'll still need to supplement these