Temp fluctuations

[howmanyds]

Is it usual to have the temp in a small tank (15g) fluctuate with a submersible heater? I'm on my third one (this time an eheim jager) and it heats to 78.8 and then drops to 77.4 before heating back up again. The others I tried had up to a 4° fluctuation.

Isn't this bad for my cichlid fry who are sensitive to changes?

 

[lordT]

What name brand? I would think temp swings would not be that great for fry. A degree of fluctuation isn't that bad but 4 to 5 degrees is a large swing.

 

[howmanyds]

The current one is eheim. The previous ones were viaAqua.

 

[Brookster123]

Have you checked the thermometer? Maybe it's the issue?

 

[pip walters]

The fluctuation shouldn't effect the fry, unless it is a sudden drop or rise. Water cools relatively slowly and fish in the wild can be subject to quite substantial variations in the course of a day.

 

[Old Scales]

A one degree plus or minus from set point is the normal on/off/on cycle for any heater. OS.

 

[howmanyds]

I just never had that problem with my 75 gallon and an in-line heaters on each of two canister filters. The temp seldom varies more than 2/10 of a degree.

Since my fish are from Lake Tanganyika, where the water values don't change much, I've read that small changes can sometimes be upsetting. But as long as a degree or two won't hurt over the course of a few hours.