And she doesn't just love the physical benefits, but the new friends and support network it creates.

She takes part in Arthritis ACT's regular hydrotherapy pool sessions.

But Joan and many others are worried about how they will continue to get their hydrotherapy sessions when the Canberra Hospital pool closes in the middle of the year.

The government says the pool is too old and the classes can be managed through the University of Canberra Hospital pool that opened last year, and other pools in the territory. 

But Arthritis ACT CEO Rebecca Davey is concerned they will have to turn clients away due to capacity issues, while some users will not be able to travel to the north.

Health Minister Meegan Fitzharris promised in estimates last year the new Stromlo pool would have a hydrotherapy pool in it.

But it has since emerged the pool is not warm enough to be classified as a hydrotherapy pool and is not able to be used for therapeutic reasons.

Ms Davey said the pool needed to remain open until a new one was built.

"We can save so much money keeping people out of hospital," she said. 

"We would like them to maintain the Canberra Hospital pool as a priority and allow the community - either through us or through some other body - to access that pool for all the hours it could be accessed.

"If that pool comes to the end of life, put in another pool somewhere on the south side. These people are all going to get sick, they're going to end up in hospital."

She said they had been trying to get more time in the University of Canberra Hospital pool but had not been successful.

They'd also recently lost access to a Black Mountain School pool they were previously able to use.

"We're actually getting less and less time for hydrotherapy and yet our numbers for hydrotherapy are skyrocketing," she said.

A spokeswoman for Ms Fitzharris said the government was currently exploring other options in Canberra's south, with discussions under way with Calvary John James Hospital for further sessions to be made available at their pool.

"We understand the need for older Canberrans to have access to hydrotherapy services and we want to assure Arthritis ACT members that we will continue to work with them to ensure users can access alternative hydrotherapy and warm water pools," she said.

"Arthritis ACT have said they understand the pool has to close soon, and have said they are committed to working with us to come to alternative arrangements for their members who rely on hydrotherapy. We are also working with them to further understand a recent growth in demand that has only recently been bought to our attention."