Fullofit343

Right now i have a 200 watt heater on my 75 gallon aquarium. It's turned al the way up and the temperature won't go up past 73.5 degrees. I've tried boiling a few pots of water and putting it back in the tank bringing the temperature up to 77-78 but again it would just drop back to 73.5 so i'm thinking about replacing it with a 300 watt heater. Would that work better?

sirdarksol

Either replace it or add another heater. I had to do that with my guppy tank. Neither of the current heaters are enough to keep the tank fully heated on their own, but at least if one of them goes out, the tank won't instantly drop to the low 60's of my living room.

galvatron3000

200 watts should be enough but you should have 2 heaters, put one in the sump and allow the water from the sump to heat the main display. Use the second just incase the other goes bad and keep it inside the main tank. I have a 210 and I use only 2 heaters and they work fine, at first I only used 1 and it worked great. Mine are rated around 250 I believe, they are Eheim heater found at Dr Fosters...

sgould

I had the same issue with the heater in my 55 gallon. I added a 2nd heater, keeping the first as well, and the temperature has held very steady at set point ever since.

Oil_Fan

Add me to the list of having to add a second heater to 65 gallon tank. During the winter, I found the one heater wasn't enough to keep the temperature high enough. Added a second one in my sump and haven't had an issue since.

aquarist48

I have 2 250w stealth heaters in my 155g. Having 2 helps to eliminate cold spots in the tank.