Im toying with idea of using element heaters as well. Not necessarily for stuborn cleans as 99.9% of my work is regular maintenance. So its just for making hose supple n little warmth for those cold starts.
As theh are used overnight, and appreciate heat cycles upwards etc, how high up from base of tank is best place to install? My tank is 500ltr upright. Thinking need a really long arm to secure on the inside tank