this will be my 3rd, i dont know what you call it temp adjuster. its the black rectangle top rounded temp controller i have got to read just all the time the first one never worked i need a new temp controller. I was told to contac you guys because foster no longer carries this product. This will be my 3rd controller. pls help. have had less than 2 or 3 months. Also the first one was sent back to get a new one. But 2nd does not keep a constant temp. Help me the temp should be 25c to 26c but it can go way lower and way higher.