# Annotations

Annotations are an important feature of the Oceanograph platform that allow you to keep track of key events and changes in your reef tank over time. These annotations can include a wide range of information, such as water changes, dosing of products, changes in livestock, or personal notes.

When you add an annotation to your tank, it is fixed in time and linked to the history chart of your tank. This makes it easy to see exactly when a particular event or change occurred, as well as how it may have affected the health and vitality of your tank.

The history chart provides a detailed record of your tank's history, allowing you to track changes and identify trends over time. This can be a valuable tool for troubleshooting issues, optimizing your tank's performance, and making informed decisions about your tank's care and maintenance.

# Water Changes

See: Water Changes

In the Oceanograph platform, water changes can be added as an annotation to a reef tank. This is important because it allows reef tank owners to keep a record of when water changes were performed, how much water was changed, and any other relevant details about the process.

By keeping track of water changes in this way, reef tank owners can monitor the frequency and volume of water changes over time, and ensure that they are maintaining optimal water quality in their tanks. Water changes are a key element in the overall care and maintenance of a reef tank, as they help to remove excess nutrients, pollutants, and other waste products that can accumulate over time.

# Dosing

See Dosing

In the Oceanograph platform, dosing of supplements or other products for reef tanks can be added as annotations. This is important because it allows reef tank owners to keep a record of when dosing occurred, how much of a particular supplement or product was added to the tank, and any other relevant details about the process.

By keeping track of dosing in this way, reef tank owners can monitor the dosing frequency and amount over time, and ensure that they are providing their reef tank with the optimal levels of nutrients and other supplements. Dosing of supplements such as calcium, magnesium, and alkalinity are critical to maintaining the proper water chemistry required for healthy coral growth and overall tank health.