I have been in training more than 4 weeks, it has cost me hundreds of dollars in travel. Believe me, I feel no different than I was in center dialysis. I still am weak after the nxstage treatment and still don't get great results as promised.
I was in ESRD for 7 years before having to start dialysis. Before I even started, I knew I wanted daily home dialysis. I began in-center and it took me about 2-3 months to work up the courage to place my own needles. After that I began my training on the System One. They told me it normally takes 4-5 weeks to complete the training. I finished in just over 1 week.
Once my equipment arrived I went home and enjoyed relaxing at home doing my own treatments with my wife and 1 year old daughter.
10 months later I was blessed with a transplant from a good friend from my church.
To answer your questions...
"...How does the water work? Can you use tap water or do you need special distilled water or some other kind of purified water? ..."
It depends on your center's preference. Normally (like with my center) they also supply you with the NxStage Pureflow SL water filtration system. It connects simply to your household plumbing by a couple different methods. I would make a "batch" of dialysate every other day under my prescription (some can get 3 treatments from a batch). The alternative is to use pre-mixed 5 litre bags of dialysate. This method requires a LOT more storage space for your supplies.
"... how important is it to have some kind of supporting figure to help in your opinion?..."
Personally, it was not necessary. It is nice to have someone else around and again, depending on your center's policy it may or may not be required. When I was dialysing at home, I always put myself on before she came home from work. She would then make dinner and take care of our daughter and some chores. My treatments would last about 4 hours. Most of the time I would also take myself off the machine as well. My wife did receive a couple hours of "assistance" training where we showed her where I would potentially need help and what to do in "worst case scenarios".
Regarding the original poster's statements...
When I was in-center, I never noticed any adverse effects except once or twice they pulled too much fluid off and I began to cramp badly in my legs. I never experienced the wash-out feeling some people experience.
The same was true with home-dialysis. No ill effects.
Within the 5-8 days I began training, I was able to stop taking my blood pressure medication altogether. My blood pressure was the best ever since I was in my 20's. I was 42 when I began dialysis and 43 when I received my tranplant.
In-center I would receive only 3 treatments per week (government standard approved by Medicare). With home dialysis I started with 6 treatments per week, but I negotiated with my nephrologist and he ok'd me to do only 5 per week, giving me an extra day off each week.
The difference in my labwork compared to when I was dialysing in-center was like the difference between night and day.
My nephrologist told me in-center you only receive enough treatments to keep you alive. With daily home dialysis, it keeps you healthier extending life-expectancy, eliminating the highs and lows (wash-out feeling) in-center patients experience and makes it a lot easier to live your own life, not being tied to a center so to speak.
I live in Washington. My wife and I took a trip to Arizona, taking my equipment and supplies with us and I did a couple treatments down there in the hotel we stayed at. (Note: life-sustaining medical equipment and supplies fly for free and are given priority handling. First on the plane and first off the plane.) One Homeland Security official was not humored when I jokingly told him to be careful with the cases my equipment was travelling in as "my kidney is in there."