Aqua-Glo fluorescent bulbs range in length from 12 inches to 48 inches for larger aquariums, and from 18 inches to 36 inches for medium-size aquariums.
The lifespans of the Aqua-Glo fluorescent bulbs vary, with the shorter bulbs having shorter lifespans, and the longer bulbs having longer lifespans. For example, the 12-inch bulb can last for 3,000 hours, according to the Hagen website, while the 48-inch bulb can stay in service for up to 10,000 hours.
The cost of an Aqua-Glo fluorescent light bulb ranges from $10 to $17, depending upon the length of the product, as of April 2011. Pet stores carry these bulbs in the aquatic section, and online aquatic suppliers sell them as well.