Review on Hygger Digital Temperature Controller Aquarium Heater - Shatterproof Titanium Tube, Submersible Fish Tank Heater for 60-180 Gallon Tanks, 500W 800W Power - Ideal for Saltwater and Freshwater by Mona Kohkayne

Second Hyger heater and same problem. Even the new and "improved" model started to rust after just one week in the freshwater aquarium! And this product should be able to get into the seawater tank? And yet it cannot live a week in fresh water without rusting? Why not encase the heating plate in glass to keep it from rusting? I will send them for a new one and try again to make sure they get it right.