A study will be conducted in Adelaide to find out whether rainwater is safe to drink.

Monash University, the South Australian Department of Health and the Cooperative Research Centre for Water Quality and Treatment will carry out the study.

About 300 Adelaide families who drink rainwater will take part in the trial to find out if the water affects their health.

The families will be given filters for their tanks, but only half the filters will be real.

The researchers have chosen Adelaide because it has the highest use of rainwater tanks in Australia.

Health Department water quality adviser David Cunliffe says given the current drought, they want to be able to encourage people to use rainwater.

"This is a national study," he said.

"Interstate there are a number of health authorities who are reluctant to recommend drinking of rainwater, particularly in capital cities where mains water is available and that's because they have doubts about safety.

"So the aim of this study is to answer some of those doubts, address some of those concerns."