Here I found a digital power meter
on Ebay.
So if you want to check what devices use the most power
in your household you can use one of these or check
the power usage of your electrolysis unit:
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=6064218868 (http://partners.webmasterplan.com/click.asp?ref=284148&site=1382&subid=&type=text&tnb=32&diurl=http%3A%2F%2Fadfarm.mediaplex.com%2Fad%2Fck%2F707-3922-3266-17%3Fmpro%3Dhttp%253A%252F%252Fcgi.ebay.de%252Fws%252FeBayISAPI.dll%253FViewItem%2526item%253D6064218868)