50 watt heater in a 20 gallon tank?

Hi,
I currently have a 10 gal with a fluval m series 50 watt heater in it. The lowest room temp gets is 16 Celsius , that’s usually just in the winter at nights, and I keep my tank at 22. I find the heater works really well and it’s quite efficient. I’ve been thinking about transferring to a 20 gal tall, but buying a new heater is super expensive lol. I was wondering, what would potential issues be if I used the 50 watt in a 20 gal? I feel like it could be ok since the most it ever heats up by is 6 degrees, but i have no idea. What are your thoughts?
Thanks!

 

I suppose the risk of using an underpowered heater is the fact that it will have to work harder to keep your desired temperature, meaning it may be at a higher risk of failing. Personally I’d just go with a higher wattage heater for peace of mind - a 75w would be sufficient for your tank size.

 

25W per 10 gallons is the baseline low side. 50W per 10 gallon is high side but thats the options for heaters.
At 22 Celsius you're like 72F. In a 20g you'd benefit if having more temp control of a larger heater, 75w or 100W. You need a 6 degree Celsius swing.

You are right on the edge actually for a 20g with a 50W Heater and wanting to swing 6 Celsius. A 50W can do about 5 Celsius in a 20g, and a 75W can do about 10 Celsius. The heater is going to run constantly trying to get it. But like I said if you can run 2 Celsius cooler without hurting anything, the 50W heater will do that without overworking.

If you can live on one or two degrees short of goal, then the 50W could work but if you really need that 1 or 2 degrees, a 75W or 100W is really what you need, the 100W being the better choice because it won't run as long to maintain the temperatures you want.

 

25W per 10 gallons is the baseline low side. 50W per 10 gallon is high side but thats the options for heaters.
At 22 Celsius you're like 72F. In a 20g you'd benefit if having more temp control of a larger heater, 75w or 100W. You need a 6 degree Celsius swing.

You are right on the edge actually for a 20g with a 50W Heater and wanting to swing 6 Celsius. A 50W can do about 5 Celsius in a 20g, and a 75W can do about 10 Celsius. The heater is going to run constantly trying to get it. But like I said if you can run 2 Celsius cooler without hurting anything, the 50W heater will do that without overworking.

If you can live on one or two degrees short of goal, then the 50W could work but if you really need that 1 or 2 degrees, a 75W or 100W is really what you need, the 100W being the better choice because it won't run as long to maintain the temperatures you want.

Right, that makes sense! I have a cherry shrimp only tank so it’s possible that I could lower the temp. Thanks for your help!