Mr Tumarae said there were different challenges including the bronze level 30-hour challenge, the silver level three-day challenge, the gold level three-week challenge and the platinum level 30-day challenge.
He said people could still drink non-flavoured milk, drinks like unsweetened coffee and tea and green teas but the aim was for people to cut back on sugary drinks and artificial sweeteners and increase water consumption.
Mr Tumarae said there had been a lot of interest from people who said they were addicted to energy drinks and wanted to use the challenge as a way to stop that.
While it was focused on kids, it was open to anyone.
He said it worked towards a goal of having all schools water only by the end of the year.
"Because I work in schools with kids that's my passion."
One of those taking part is Lisa Ardern. Working at Mountain View Preschool, which is also taking part, she's involved in helping the kids learn about the importance of water - and has decided to walk the talk.
Ms Ardern said the hardest part for her would be giving up the sugar in her tea as well as soft drinks. "It's the fizzy drinks I am going to struggle with. I have a very bad sweet tooth." She plans to cut out sugary drinks for all of April. While the preschool only offered water for the children, and the occasional Milo in winter, Ms Ardern said they held a lunchbox day once a week where kids could bring whatever drinks they liked.
They'd be encouraging kids to bring water during April and running fun activities around how water affects plants, what happens if they don't have enough water and talking to the kids about why it was important to drink water.
-Those who want to find out more can join the Free Fit - Rotorua Facebook page.