The AquaLife glass combination hydrometer and thermometer measures specific gravity
and temperature of saltwater aquariums. The hydrometer measures specific gravity
from 1.00 to 1.06, which is readily converted to salinity with a conversion table.
The thermometer measures temperature from 0-40·°C and 40-100·°F in increments of 1·°C
or 2·°F. The green areas are the ideal ranges of temperature and specific gravity
for most saltwater aquariums. Readings falling on either side of the green area
indicate an adjustment of the salt concentration is necessary.