The Seneye is a warning system for your tank. The digital monitor connects to the internet and continually checks up on the pH, temp, and ammonia levels of your aquarium, alerting you if anything is out of the norm. The system monitors the pH and ammonia via small sensor pads that are replaced every 30 days at a cost of around $100 per year. The system can also be configured with a light meter that measures PAR, Lux, Kelvin, and spectrum, which allows you to monitor these parameters live as you configure your lights. Connect with us on Facebook: http://www.facebook.com/BulkReefSupply Check out our pics on Instagram: http://instagram.com/bulkreefsupply