The most important way to dose your tank is to perform regular water changes. In addition to removing wastes, fresh saltwater also brings an influx of minerals that have been depleted back into the aquarium. This may not be enough on its own, but it is still the most important thing you can do to keep a healthy aquarium.

Before you pour anything into your tank, it is important to understand what you are adding and how much you need to add. You can easily throw off the parameters in your aquarium if you start indiscriminately adding things to your water.

So, your first step is to test your tank water. But which tests should you perform?

We recommend at least testing for calcium and alkalinity. We strongly suggest magnesium as well. This is, of course, in addition to testing for water quality parameters like nitrate and pH. Test weekly and record the results in a tank journal, log or blog. While not particularly fun, it is necessary if you want to see what effect dosing has on your system. A brand-new system may not need calcium, but as it matures and corals grow, so will the demand.

After testing, you will know precisely where things are at. Now let's cover where they should be.

We recommend keeping calcium between 400-450 ppm (parts per million), alkalinity between 8-12 dkh and magnesium around 1300 ppm. While these ranges are acceptable, you should always shoot for stability in each of them. For instance, if your alkalinity is at 9 dkh, you should try to keep it there instead of dosing it up to 12 dkh and waiting until it fails to 8 dkh to does again. Like most aspects of aquarium upkeep, keeping things stable is one of the keys to success.

The most popular method is to use a 2-part dosing system. The main ingredients are split into two bottles, calcium and alkalinity. 2-part systems are designed to dose all the important minerals in the same ratio they are used in your tank. For most aquariums, this is enough to keep things stable. The more frequently the system is dosed, the more stable conditions will be. It is better to dose small amounts daily than to dose large amounts infrequently.