Safe H2O uses a bio-fuelled mobile unit with a nano-filteration system processing 20,000 litres of water each hour.
Mr Campbell said the challenge in getting the task done previously was to empty the tank and have someone climb inside to scrub it.
"Quite often the inner walls of the tank get damaged in the process and then owners have to pay to get more water delivered."
Mr Campbell said with Safe H2O all the water was retained and all sediments and pathogens removed.
"A lot of people are aware of the bacteria in their water but put cleaning the tank in the too-hard basket.
"They get used to the water that's in there but it can cause problems when visitors or children come to drink that water and aren't used to the water because they haven't built up that immune system."
The couple have spoken with others who have experienced similar issues with their water tanks, and they believe their new business venture will be a great success.
"We are really excited to get started."