When starting with corals you won't need to dose anything. As stated above water chAnges will replenish depleted levels in your tank. The problem arrises once you have more coral and they strip what they need from the water faster and in greater quantities. This is when a person faces a choice- increase water changes or turn to dosing. Dosing is the preffered method by experienced reefers because water changes are time consuming and cost more down the road. If a person does a 15g water change every two weeks and has to increase that you would move up to 15g every week. Double the water used, double the salt plus it now means replacing your rodi
filters in half the time. This is where dosing plays into the mix, Can maintain a regular water change schedule but in the beginning it does require a little time attending to the aquarium to figure out the balance needed to maintain levels. As a basic rule dosing is done for alkalinity and calcium levels, calcium is what the coral makes its skeleton from and the alkalinity (carbonate hardness) is the glue to hold the calcium together. Your alkalinity level should be maintained between 7-11, I try to keep mine around 9. Calcium should be in the low 400's, 380-450. when dosing for these two things its important to understand that one thing effects the other and dosing should be done in small amounts and spaced out. DON'T DOSE BOTH AT THE SAME TIME, this will lead to a snow storm in the aquarium. The alkalinity dose will react with the calcium dose and precipitate (the calcium and carbonate will bond into small clumps and fall out of the water column). There are many choices available to dose, kalkwasser is a popular one as is one of the many 2 part systems. Personally I'm going to try 2 part as its time for me to start dosing. There are also many ways to dose, you can manually dose it (best to be added to the sump so it dissipates before reaching the main tank), there is the option of adding your dose directly to your ATO water (best for kalkwasser) and there is automated means. You can find dosing pumps to dose for you or you can run a simple drip, both should be done into the sump. A drip is just like acclimating fish, airline and valve to adjust flow. Hope this helps.