I've used tap water and house water all the time. I still do. The only thing I could say about tap water is to be sure that there isn't too much sulfer, chlorine, or heavy metals in the water. Rust could be bad too. You can check for these things by going to your local gardening store or regular store and look for a water testing kit. They're around 10 dollars or less over here state side. Good Luck and Have fun.
Another place you can look for the water testing kit is a place that sells aquarium supplies. They always have things like these.
~ Ken ~