Review on Enhanced 500W Aquarium Heater: Auto Thermostat, LED Digital Display, External Temperature Controller - Ideal for Saltwater and Freshwater Tanks by Savanna Wilson

Both heaters tested with wall meter and they only draw 400w each not 500w as advertised. Also, after a week of use, they developed resin crystals that appeared to be leaking from the cap at the end of the heating tube. The only reason they got two stars is because they work well and have held the set temperature well so far. Spend a little more and get a better product if your intended use is crash sensitive. Update after 2 months of use, both heaters started shorting out and sending electricity into the water, luckily I noticed this without major injury. Stay away from this brand