Originally Posted by shinybetta
No, it is three to five watts per gallon. So, you would want an 8-12 watt.
TBH, I use 25 watt submersible, adjustable heaters in my one 2 gal. bowl and in my two 3 gal. bowls and they work fine. Just had to fuss with them a tad the first couple of days to make sure the heaters weren't set too high.
For example, if you set the heater to 78 for a small enclosure like 2 -3 gals. it is going to be much warmer than 78. Under those conditions, I normally will set the heater to 72, monitor it & adjust from there.