Heater

[sergifed91]

Not sure what I should get for a 125 gallon tank. 300, 400 or ,500 water heater.

 

[Red_Beard]

I would go with 2 300 watt heaters. both of them together would be needed to keep your tank at temp. If one fails on, it can't overheat your tank. if one fails off, it won't freeze out.