Need hlep with temp swings!!!

OKAY!!!!!! I just found out something! My heater was NOT Plugged in over night, so thats why it got so low, i left it unplugged for now, the tank has raised 5 degrees from just the lights, ill let it get to the 78 range and turn on the heater at 77 degrees so it shouldnt fall below 75.
Hopefully this will solve the problem! My nem has not opened up completly today, so hopefull when i get this temp solved out it will be happy.

 

Okay the tank is at 79 degrees!!! it raised about a degree an ahour or so. Is this still gunna be okay? I am going to turn on the heater so it wont go below 76 at night, but will the MH still keep heating up the tank?

 

Sounds like a good idea to turn on the heater to maintain min. temp of 76.I doubt if it's just your light raising the temp that much,could be due to the ambient air temp.It's probably a pretty warm day in s.c. Temp should peak soon,79-80 isn't bad,if it goes much higher than that;say above 82 you might need to try some cooling measures such as directing air from your fan across the water surface or changing your lighting schedule.

 

Okay, so today, i turned on MH and temp was at 76, after working, came home about 6 hours later and it was only at 80.1 So i think that is where its peaking..