Using 150 Watt Heater In 10 Gallon Tank..pros, Cons

[Fishmanic]

I received a 50 watt heater with my marineland 10 gallon aquarium kit.  It is a no name heater and seems to be a very basic heater though it has a thermostat.   It does not have a temperature indicator so you have to experiment to get it set right.   So far it does not seem stable in my 10 gallon tank
 
I also have a new Visitherm 150 watt heater that I never used but had it in storage as a backup heater. It has overheat protection, has a nice dial click indicator and also a side scale for setting the temperature.  Is there any drawback to using this heater on a 10 gallon tank.  Would the temp be stable using this oversized heater in such a small tank?   It is rated for use in up to a 40 gallon tank.
 
Or am I better off going with the 50 watt simple heater or upgrade to a better 50 watt heater?
 
What would you advise?

 

[NickAu]

As long as the thermostat works and it fits in the tank I cant see any problems,  I have a 75 watt Aquael easy heater in my 5 gallon cube and it works perfectly.

 

[AbbeysDad]

I tend to agree - as long as it's properly submerged and functioning properly, a higher wattage heater should be fine.
Just for reference, I 'could' use a single 150w heater in my 60g, however I have two 200w heaters. They work in sync so neither is working too much and should one stop working, the other will maintain the proper temperature.

 

[DWC]

The only caveat in using a powerful heater is if it does "stick on" which I've only experienced once it will overheat the tank much faster, perhaps too fast for you to intervene. In my case I lost a 10 gallon community tank's residents. After that episode I actually used two under powered heaters for a time, thinking if one failed or overheated the other would be able to at least the tank livable or it would overheat much more slowly. This became a pain as my tank count grew so now I use single 100w heaters in 10 gallon tanks, slightly overpowered but I keep my house at 60F all winter and the tanks at 78-80F so there is significant differential to make up.

You could "install" the 50w heater ALSO but set it slightly colder than the primary so it theoretically never comes on except in case of the primary's failure, hence insurance.

David

 

[Byron]

I have found the 50w heaters less reliable than any of my 100w, 150w and 200w heaters over many years.  I cooked a 30g tank of fish with a 50w that overheated at night.
 
I have a 150w in my 10g, and have for several years.  I only have 150w and 200w heaters in the other tanks.
 
Byron.

 

[StevenF]

you can calculate the minimum amount of power needed for your aquarium using this calculator:http/www.kernsanalysis.com/CalcMinWatt.cgi?LENGTH=8&SIDEUNIT=INCH&TOPTHICK=.125&WALLUNIT=INCH&WIDTH=8&WALLTHICK=.125&HEIGHT=8&BOTTOMTHICK=.125&WALLTYPE=ACRYLIC&SUPPORT=FELT&DELTAT=15&TEMPUNIT=F&.submit=Submit
 
the amount of heat needed and will very with the size of the tank and the materials it is made from (glass or plastic).
 
based on my own experience with a small tank and using this calculator you probably only need a 20 W heater to maintain water temperature.  Bigger heaters will work but if it fails your fish will be dead by the time you discover the failure.  Also a large heater may cycle on and off rapidly when it is heating the water right after a water change or a cold night.  This cycling of the internal switch on and off rapidly may reduce the life of the switch making a failure more likely.   In contrast a heater just big enough to do the job will stay on for longer and therefore have fewer on and off cycles and may last longer before it fails.  
 
In my opinion using the smallest heater possible is the best solution.  If the small heater sticks on it might not be able to overheat the tank.  Or if you use two heater rated at 1/2 the power needed and one sticks the remaining good heater will stay off and your tank is unlikely to overheat.  

 

[Byron]

My own experience shows your conclusion is not accurate.  A 50w heater in a 33g (3-foot) tank remained on overnight and raised the tank temp from 76F to 90F and fish died before I saw this in the morning.
 
The larger wattage heaters also tend to be better made.