2. Which is better: glass or stainless steel? It's hard to say; each has its advantages. Generally, glass ones are inexpensive (except for some special processes), widely used, and can be applied in various aquariums. The disadvantage is that they are easy to break. If used in large fish tanks, a protective cover must be installed to prevent fish from breaking them. The advantages of stainless steel are obvious: sturdy, durable, and aesthetically pleasing. However, the disadvantage is that they cannot be used in corrosive environments, such as saltwater tanks.
3. Quality: Actually, domestic products are good enough; there is no need to buy imported ones. Brands like Jiabao, Chuangxing, and Yinsheng are decent. I am more supportive of domestic products. The quality of heater rods can be distinguished in many ways; expensive ones are not necessarily reliable. Some expensive ones use different glass and heating wires, and some have added anti-explosion features to prevent glass shattering. If you are not careless, these features may not be useful to you. This greatly affects the price of heater rods, but if the bimetallic strip fails to trip, high-end heater rods can cook fish soup faster. As for stainless steel ones, many use electronic temperature control, with a thermistor to detect water temperature, which then controls a relay or high-power thyristor to switch the heating tube on and off. This accuracy is higher than that of ordinary bimetallic strips, but if the thermistor or thyristor fails, the heating speed will be faster than that of ordinary glass ones.
4. Repair of heater rods: If it is a glass one, usually the glass is broken, so you need to replace the outer shell. There are specialized glass tubes available on the market. When replacing, be careful not to move the adjustable screw on the bimetallic strip, otherwise the temperature control will be inaccurate. Also, ensure a good seal to prevent water leakage (this can be considered common sense). Stainless steel ones generally have little to repair; if broken, it's best to replace the whole unit. If it is an externally adjustable one, you can take it to a general appliance repair shop and ask them to check it; most likely the thyristor is burnt out.
5. What size heater rod for what size tank? Generally, calculate the water volume of the tank. 1.5W to 2W per liter of water is best for heater rods. For example, if my tank holds 100 liters, I can use a 150W to 200W heater. For large tanks, such as those holding 300-400 liters, a 500W heater should be used, but it is better to buy two 300W heaters. This has the advantage of faster and more uniform heating, and you can place one on each side of the tank. Moreover, if one fails, it won't rapidly raise the water temperature.
6. Usage experience: If the outer shell of the heater rod breaks during normal use, don't panic. Generally, it won't electrocute the fish. Just unplug it and replace it. Many netizens accidentally forget to unplug the heater rod when changing water. As the water level drops below the heater rod, the rod heats unevenly and the shell cracks. If there are fish nearby, then... Under normal use, it usually doesn't break; it's often due to not unplugging when removing it for water changes or cleaning, or accidentally hitting it against hard surfaces. Remember to unplug it and wait a while before removing it, otherwise the residual heat can be harmful.
