crystals on outside of heater?

[cajungrl81]

During the fishless cycle in one of my 30gs, crystals began forming on the outside of the heater. Is the heat causing minerals to precipitate out of the water? Or is something else going on? Should I remove the crystals before putting in the fish, or will it be safe as-is? Both aquariums are fresh water, and this only happened in the tank with the higher heater setting

 

[fort384]

Yes, this happens occasionally, should not be any cause for alarm. You can remove the heater and clean it off if you want, but it won't hurt anything.

 

[wildroseofky]

I would clean them off if there gets to be too much. It will interfere with the heater working. That is what kills your hot water tank. You can turn the heater off and clean it with a rag dipped in vinegar. Vinegar will dissolve the build up and is safe to use around the tank.