Fibromyalgia Support Group
You're not alone in your pain. Fibromyalgia is a condition that can be difficult to diagnose and manage. If you're trying to cope with pain throughout your body, sleep problems, general fatigue, or other common fibromyalgia symptoms, you're in the right place. The community is here for you to talk about therapies and share your challenges.
I went for some aqua therapy years back and I recall reading somewhere that it is important for the water temp to be within a certain range. I've never heard of what you are describing--I hope if you find something out, you'll let us know.
Read the comments here - rawarrior.com/rheumatoid-arthritis-swelling-take-two/?show=comments#comment-73966
Many people with RA have slight swelling and some swelling that's not visible on clinical examination.
Have you had an MRI?