Wow, Great deal!
OK, If you have researched these boards, you will see that Tap water carries all sorts of problems with it. I made the mistake of using tap water initially, thinking that because it was well water-no problem. However, it was full of phosphates-from fertilizers and who knows what else-took a while to clean it up.
RO is recommended. Steam distilled is ok. If you have to use tap water, I would have it tested for metals and all the other stuff before using it for the tank.
It is so much easier to start right-a lot easier than cleaning up our mistakes after the fact.