Been a non-registered reader for a while, but decided it was time to pop up and say something

So, I've been a user of a Lamy AL-Star w/converter and Diamine black ink for a short while now, (just popped on a 1.1 italic recently). I've flushed and cleaned my AL-Star regularly with tap water and haven't had an issue. Here's my question though; I've recently been giving a new Lamy 2000 and I've heard people say that distilled water is best etc. Now, I intend to flush my Lamy 2000 before inking it up and I just wanted to see what people thought about using tap water? Is it just being a little pedantic to use distilled water and tap water will be fine?
The tap water in my location (Manchester, England, UK) is good quality and not "hard" water, I and others drink it and notice no issues.
Also, I'm lead to believe that distilled water isn't as common or easy to source as it is in the USA.
What's your thoughts?
Thanks and regards,
Scott.