lugiex

what heater/heaters should i use to heat a 125 gallon tank?

pinkfloydpuffer

I would use 2 heaters for that size tank, to make sure it's heated evenly. The Marineland/Visitherm Stealth heaters are really great.

capekate

I would suggest at least two 250 or 300w at each end of the tank.

lugiex

any specific brands or specific heaters that one would suggest?

capekate

There are quite a bit of good name brands out there to choose from. How much you want to spend is really the question. I would suggest tho, not buy a all glass heater, and I would also suggest getting a submersible heater and not one that hangs off the back of the tank.
Visa Therm is a good brand, The stealth by marineland is what I am using on my 125. But there are a lot of great name brands out there.

agabr123

marineland visi-therms are my favorite, and they also have a lifetime guarantee