I have a 300 gallon plastic IBC tank buried in the ground in my green house with 282 Tillapia in it in various sizes. Tilapia will die if the water gets below 60 degrees for very long and below 70 degrees they don’t eat much or grow. So I have a hot water heater element in the side of the tank with an electronic temperature controller hooked up to it to keep the temperature right at 75 degrees. I went out to feed my fish this morning and the water temperature digital display screen said 85 degrees. What!! How can that be? I stuck my little handie dandie thermometer into the water and it was down to 62 degrees, oooooooo that is not good!! the temperature controller had obviously malfunctioned. I quickly wired the heating element direct so it was on continuously while I tried to fix the problem. I played around with it for an hour trying to get it to work, but it seemed like it was toast. I had another one in my aquaponics box of stuff for a back up, but when I got it out of the box to hook it up the instructions were all in Chinese. It was a different brand then the one I had been using, but I thought I could get it wired up without the instructions. Got it all done and flipped the breaker on and I fried my controller! Oops, that wasn’t very smart!! Meanwhile I kept checking the water temperature and turning the electricity off and on to my heating element to keep the water close. Then I did what any smart person does, I typed in “how to fix a Racon electronic temperature controller”, on Utube on my IPad. I watched several videos that sounded like my problem and I gave it a shot. Got done, hooked it up and success, it works. I now have a new skill.