400Parker
Registered

Tap water may be fine for you Johnnie, but unless you live in an area with exceptionally soft water, the boiler on your loco will eventually fur up like a kettle - except it won's be as easy to clean. Have a search on the forum about water, because this topic comes up fairly regularly.
However the quick answer is either filtered rain water, or distilled water obtained from a de-humidifier. You can buy a de-humidifier cheaply and it can be used to dry out rooms or the washing while it makes distilled water for your loco!
There's been a lot of discussion on the forum and others about the whys and wherefores of de-ionized water, but in the end buying 'distilled' water rather than making it yourself is usually a costly exercise.
Try here http://www.gscalecentral.net/tm?m=61152 or here http://www.gscalecentral.net/tm?m=2477
Steve
However the quick answer is either filtered rain water, or distilled water obtained from a de-humidifier. You can buy a de-humidifier cheaply and it can be used to dry out rooms or the washing while it makes distilled water for your loco!
There's been a lot of discussion on the forum and others about the whys and wherefores of de-ionized water, but in the end buying 'distilled' water rather than making it yourself is usually a costly exercise.
Try here http://www.gscalecentral.net/tm?m=61152 or here http://www.gscalecentral.net/tm?m=2477
Steve