50 Watt Heater

[lilfishie]

Well as the title says would a 50 watt heater be too much for a 3 or 5 gallon tank, the 5 gallon currently has a 25 watt heater which i found a while back (haven't been able to find them again since)

Anyway the reason for this is i need to seperate my guppies before they start inbreeding.

Idealy i would like to have the smaller heater in the 3 gal as it is plastic, the 5 gal is glass.

Many Thanks for any help Lil

 

[MermaidMel]

Well as the title says would a 50 watt heater be too much for a 3 or 5 gallon tank, the 5 gallon currently has a 25 watt heater which i found a while back (haven't been able to find them again since)

Anyway the reason for this is i need to seperate my guppies before they start inbreeding.

Idealy i would like to have the smaller heater in the 3 gal as it is plastic, the 5 gal is glass.

Many Thanks for any help Lil

Look on Ebay for 25w heaters or other online aquarium stores. 50w would be ok short term just keep a thermometer in the tank just in case.

 

[ox5477]

I have heard of a rule that 5W/gallon is how to size your heater. But of course you want to have a lttle extra power to make sure your tank stays at temp so the 25 is perfect for the 3 and a 50 would be fine for the 5 as long as it fits in the tank

 

[loachman]

Typically, you'll see much shorter life from a significantly overmatched heater and larger temperature fluctuations. The reduced lifetime is a result of the frequent on/off cycling.

 

[Fineas]

The Newattino Plus is perfect for very small tanks. It is totally sealed making it ideal where young fry are around. I have one in my small QT and reckon it is one of my better buys.

Ken

 

[Piltdownpaul]

i use an old 100w in my 16litre 3gallon-no probs-as you know the tank is in the garage -hence the wattage being a bit higher to cope with lower external temperatures

 

[fry_lover]

Typically, you'll see much shorter life from a significantly overmatched heater and larger temperature fluctuations. The reduced lifetime is a result of the frequent on/off cycling.

why would the heater go on/off so many times if its overmatched?

disagree with larger temp fluctuations as well

for the original poster, the smallest heaters i have are 50W and i have used these for months on end in my tiny fry tanks (which range from 10 litres to about 20 litres, i.e 2.6 US Gallon / 2.2 UK to 5.3 US Gallon / 4.5 UK) and i have not noticed any of these temp fluctuations as mentioned.

I think ideally you want a 25W but a 50W set on a low reading (i set mine to about 20-22C) seems to work fine for maintaining a 25-27C temp

 

[three-fingers]

Typically, you'll see much shorter life from a significantly overmatched heater and larger temperature fluctuations. The reduced lifetime is a result of the frequent on/off cycling.

why would the heater go on/off so many times if its overmatched

disagree with larger temp fluctuations as well

for the original poster, the smallest heaters i have are 50W and i have used these for months on end in my tiny fry tanks (which range from 10 litres to about 20 litres, i.e 2.6 US Gallon / 2.2 UK to 5.3 US Gallon / 4.5 UK) and i have not noticed any of these temp fluctuations as mentioned.

I think ideally you want a 25W but a 50W set on a low reading (i set mine to about 20-22C) seems to work fine for maintaining a 25-27C temp

Because heaterstats work by turning on down the temperature drops a detectable value below what they are set to, and larger heaterstats heat the water faster.

For example in a 5 gal with a 25watt heater set to 25C, when the temperature hit maybe 24C or 24.5C it would turn back on and heat the water until it was 25C again.
With a 100w in a 5gal, this happens more regularly and faster because the higher powered heater heats the water to 25C much faster and turns off, at which point the water cools down again. There are sharper frequent small increases in temperature - but IMO these are no problem at all, fish swim in and out of different temperatures all the time.

I personaly would never put a heater that was significantly larger than needed in a tank long term - the heater is the piece of aquarium filter that most commonly fails, and turning on/off constantly probably isn't a good idea.
Short term the risk of anything breaking is fairly low and, so no problem, but just always be on the lookout for a smaller heater just to be safe!

 

[fry_lover]

thats why i set mine to 20-22

but yeh smaller heater be better, i wouldnt ideally use a 50W on 10-20 litres but its all i had

 

[lilfishie]

well managed to track down another 25 W today so its all sorted thanks all.