I recently bought a new submersible heater from petco and just started using it today in the afternoon on my 20 gallon tank, the heater is from aquatic gardens its a blue colored one.
i dont think it works, the water is still cold and i dont want my turtles to get hurt during the night. Does it take 24 hours for the heater to warm the tank up? I have another heater from top fin for my ten gallon tank and it worked fine but i dont use it anymore since i upgraded everything.
does anyone have or had a problem like this with a submersible heater?


