Alkalinity is the single most important parameter in a reef tank, IMO. Alkalinity is increased by adding sodium bicarbonate or some variation thereof. Calcium is the next most important parameter, and increasing it is either done with calcium chloride or calcium hydroxide additions (kalkwasser). Calcium additions with kalkwasser are OK by themselves (the hydroxide ion doesn't upset the ionic balance, only raises the pH). Calcium additions with calcium chloride without alkalinity additions can lead to an increase in chloride ions, however, which is not good. If dosed in equilibrium, the sodium from one combines with the chloride from the other to form salt, the other two ions remain in solution. If, however, the balance gets too far off, the calcium can combine with part of the bicarbonate to form calcium carbonate which precipitates out and exasterbates the problem.
Bottom line, invest in an alkalinity test kit at a minimum! They are cheap and easy to use. I wouldn't dose anything "chemical" I couldn't test for. With one coral, your calcium demand isn't that high, and Mel's advice is spot on. Also, with any ammonia, your tank is not cycled and any coral will not be happy, so you should be doing very frequent water changes to keep the ammonia levels down until the cycling is complete.