Help!!!! Aquarium Heater Problems

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Lemonheadfish

Feeder Fish
MFK Member
Dec 11, 2018
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My Top Fin aquarium heater has been working fine for many months until now. My tank water is slowly decreasing temp but heater says it is on. The temperature outside has dropped big time and it is snowing a ton. I think I need to increase the temperature on the heater but I don't know how to do this on this certain Topfin heater there is no arrow pointing to which way I should turn to increase temperature it is just a knob that you can turn. Any suggestions?
 
maybe try reach in and turn it one way. if the lite goes out it went below the water temp and that direction was lowering temp. if the lite stays on then that direction was raising the temp.
 
Hello; I have another couple of takes on this. One is the heater may still be working but due to the ambient air temperature being lower it is not able to keep up. The adjustment knob on all the heaters I have ever used have nothing to do with the output (heating power usually described in watts).

This adjustment knob is used to adjust the thermostat of the heater. By that I mean the part which switches the heater on and off. What can happen is the heater turns on and after a time has heated the surrounding water to above the thermostat setting. Then the heater switches off for a time until the heated water mixes with the rest of the tank water. This cycle repeats. So changing the thermostat knob does not increase the power of the heater.

Here is what I do if I suspect a faulty heater. I unplug the heater and remove it from a tank. I have a metal or glass pan or some other such non-melting place to lay the heater after the test. I plug in the heater out in the air and if the light is on it will get very hot right away. If it gets hot then it is still working and the test only takes seconds or at best lest than a minute. Then I unplug the hot heater and lay it in the pan or non melting place for about an hour. ( I learned the hard way to not lay a hot heater on plastic or some such.)
 
Hello; Let me add if your heater has failed that you consider replacing it with two heaters. So if you need 200 watts of heating power to maintain the tank temp, then get two 100 watt heaters. That way if one heater fails off then the other can continue to keep the temp up for a while.

The worst case can be when a heater fails "ON". A strong heater might have the power to overheat a tank to the point of killing fish where a failed single of a pair likely will not have that much power.
 
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