Apple cider vinegar can be diluted half-and-half with water for external application, and, when stronger measures are needed, it can be used full-strength.
1 Just the stone for a flagstone patio can cost $3 -$5 a square foot or more, depending on location and the type and quality of stone, or about $600 -$1,000 for an average patio up to 10'x20,' and $1,200 -$2,000 for a larger 20'x20' area.
1 On average, plan on spending anywhere from $5 to $13 per square foot, or $1 to $3 per piece. 2  Flagstone can also be purchased by the ton if you need it in bulk for a large project. 3  It will cost $100 to $400 per ton depending on the type.