You can check it out at the hygger online store (use code Lefty3213a for 15% off) shrsl.com/44rpm OR If you prefer you can grab on on amazon amzn.to/3XC0EGl
Great info.. I personally do not like Hygger products.. they are super reasonable in price but it comes with a defective water temperature meter. The hygger heater I have marks almost 10 degrees Fahrenheit of a difference..
Woah! That's alot omg! I've not had that happen with mine. It's with I'm a degree or two of what I set it as. Did you reach out to them? They are usually good with customer service.
So yes heaters should be left in the tank all the time. Only real reason you'd be taking them out is to clean them. You should he unplugging them when doing water changes to avoid damaging them. It is rare but yes some times heaters can malfunction and get too hot or not hot enough. I have 30 tanks I maintain and have been keeping fish for 20 years on and off and I've never had a heater cook my fish or shock them. I've only had 1 heater break and not work and that was a cheap Chinese knock off from Amazon. I've had this heater in the video for a year and not experienced any problems. What size tank do you have?