Please keep all the discussion in this thread. The duplicate thread in another board is not appropriate to the question.
The VI you posted in the other thread has no independent control for the heater. If the blower is off the heater is on. Do you really want the temperature to continually cycle between the limits?
Consider learning about the state machine architecture. With a suitably designed state machine you would probably only need one loop and the fish would be happier.
As Yameada said, we will not do your homework for you but will help you understand how to use the tools (LV). Please ask specific questions.
Hint: Use booleans for the lower shift regsiters in your loops. Much simpler code.
Lynn