Well.. The 125 i picked up came with a Hydor Theo 400w heater, yet it will not heat the tank by its self. 
I had the Theo heater going and an old 150w stealth heater going and the temp was very slowly rising.
Both heaters never shut off in 2 days.
So i unplugged both and went heater shopping.
Brought home a pair of Fluval M300's and a pair of Eheim Jager 250w heaters.
Now, which pair do i use? Decisions Decisions..
Really wanted a pair of 300w Hydor ETH heaters but just havent ordered them.
Any suggestions between the two brands?
I know Eheim is great, ive got Fluval's in 2 other tanks and they seem to be doing great.
Thanks for the help to those who can chime in about my decision making.

I had the Theo heater going and an old 150w stealth heater going and the temp was very slowly rising.
Both heaters never shut off in 2 days.
So i unplugged both and went heater shopping.
Brought home a pair of Fluval M300's and a pair of Eheim Jager 250w heaters.
Now, which pair do i use? Decisions Decisions..
Really wanted a pair of 300w Hydor ETH heaters but just havent ordered them.
Any suggestions between the two brands?
I know Eheim is great, ive got Fluval's in 2 other tanks and they seem to be doing great.
Thanks for the help to those who can chime in about my decision making.