So I have a cheaper heater for my 55 gal piranha tank, the kind you turn the dial at the top to set the temp but has no actual temp numbers to go off of. My tank is kept at a even 80 last week it dropped to 70 the day after I unplugged It for water change. So today I come home to my temp at 89 and yesterday was another W/C day I never move the dial on WC days either. Tomorrow I need to just get a new heater any suggestions on what to get.
Pics of the piranhas
Sent from my iPhone using MonsterAquariaNetwork app

Pics of the piranhas
Sent from my iPhone using MonsterAquariaNetwork app