Strange issue with my heater.
I recently had a whitespot outbreak on my cardinals alone.. no other fish were affected so i treated with salt and heat and the tank is now clear.
I want to bring the temp back down to a more comfortable 26oC but am having so much trouble!
I have an eheim which i believe was correctly calibrated but it seems no matter how much i turn it down it keeps heating to around 29.5 - 30.5.
Its not jammed as the light Is cycling on and off.
Currently i have now turned it down to below 25 on the dial and the light just clicked off at 29.5.
It was 30.5 to a max 31 during treatment but i wanted to reduce slowly and have been turning down 1 degree at a time but water still heats to 29.5+.
Any ideas What is going on?