Mash water profile vs sparge water

I am making an Oktoberfest tomorrow using Distilled water with chemistry salts to match Munichs water profile but i was goin to use my municipal water with Lactic acid to get pH to 6.5 for sparge water. The water profile chemistry for my Mash vs municipal water will be different. Should i make my sparge water to the profile of my Mash water or would using my municipal water with lactic acid be fine. I dont have an RO unit so i would hqve to buy 18 gallons of distilled water at the supermarket which i dont want to do. Thanks in advance.

If you are trying to match the water profile then you will have to make sure all of your water has the same profile. Otherwise you will just be diluting your Munich water with Nebraska water and thus you will not have Munich water!

Where can i buy an RO unit at by today, lowes/home depot? I figure its better i put the money towards that than 18 gallons of water at the store.