I believe it is completely dependent on the quality and chemical content of your tap water. If you have it tested, and it seems to be relatively free of heavy metals and phosphates etc, then if you want to use it ,you should. If you don't encounter any major problems with algae and cyano
and fish death then I say it's a go. If you do, then start doing water changes with ro
water till the tap is gone or diluted. Again, as always, this is strictly my opinion based on my own experience with only one water supply.