Several companies now offer aquarium monitors that measure several different parameters. For example, the Seneye reef monitor combines a temperature probe, ammonia monitor, pH monitor, lux meter, kelvin meter, PAR meter and water level sensor all in one device.
Another great advance in the hobby is the alkalinity monitor. Reef tank corals constantly take up alkalinity. An alkalinity, or KH monitor, measures the alkalinity levels and can even signal a dosing pump to deliver more of the element.
Rather than frequently check salinity levels in your saltwater fish tank, know them with a salinity monitor, which typically uses a conductivity probe to test the level of salt in the water.
A pH monitor is superior to a pH test kit because it constantly measures pH as it changes throughout the day.