i learnt from a doctor friend that the manual one is more accurate than the digital one. This is because the digital one is calibrated and has to be calibrated regularly to maintain its accuracy!
hydrotherapy is the use of water to treat illnesses... The one I used is similar to a jaccuzi but without the strong water jets... I could pass you some information on it if you are interested...
i had a high blood pressure but was able to lower it without the need for medication. I tried hydrotherapy with the advice of my cousin and it worked for me. You could give it a try...