Advice on diluting

Made a munich dunkel yesterday and the recipe was created to achieve a 1.057 OG.
However, I'm still fine tuning my setup and recipe used 65% efficiency when I came closer to 71%. My boil also evaporates much more wort than I had accounted for.

All in all, my OG was 1.067 and I was left with about 4.5 gallons of wort.

Using BeerTools calculator, if I add .75 gallons of water Ill reach my planned OG (and final volume). My real question is;

1) What type of water do I use for the .75 gallons? Distilled or my tap?
2) Do I make any salt/pH adjustments to the make-up water?

I use EZWaterCalculator to make adjustments to my tap water for the specific recipe I brew and I reached my planned mash pH just fine. But will the make-up water effect my beer if I don't make any salt/pH adjustment(s) or is .75 gallons too little water to really effect anything?

Sounds like your boil off was more than you had anticipated. I keep bottled spring water on hand for my brew days. If I boil off to much or my efficiency was way off. I add the spring water to the pot at flame out. Being as this was yesterday instead of today....I would probably try to top off with some boiled (then cooled) water. Missing your OG by 10 points is a lot. Will still be beer.....but not the beer you wanted.

Thanks hammy, so you don't worry about making any changes to your makeup water when you need to use?

I don't, but I'm pretty lucky that my water is pretty good from the tap. It couldn't hurt to adjust for your 'top off' water I suppose if you routinely have to adjust.

You don't need to add any salts to top up water- but if you have chlorinated water, or not-great-tasting water, I'd use bottled water. Distilled, reverse osmosis, or spring water is all fine.

If you have great tasting water, with no chloramines or chlorine, that would be fine to use to top up.

This also illustrates the importance of checking your gravity before you start boiling, and having an easy way to measure volume in your kettle.

I figured out that 1gallon of liquid raises the liquid level by .84 inches in my kettle. So I always fill the kettle to the exact preboil level, then measure the gravity, and then make adjustments if I have to. Sometimes that means adding a little extra DME to reach my target OG. Sometimes I have to pull wort out and replace it with water because my efficiency was too high. If it's close I don't worry about it.

It's amazing how many all grain sessions I went through before I started doing all this - having control over your brew process is super important.