i am about to just do my 2ed all grain and i am trying to make a high gravity wort. I have 16 pounds of grain and 10 gallons of water. But i did not realize i need five gallons for my strike water and 8 for my sparging. Do you think i would be ok to use tap water for the last 3 gallons? I live in san diego just on the out skirts of downtown near little italy.