Bid a system 2 weeks ago. Out in the country. Customer has an on demand well (variable rate), and swore he had 15 gallons per minute. No sand, no iron. I give the bid, and in WRITING in the bid it says "If sand or the well will not produce 12 GPM, Contractor has the right to stop work forfeiting all work to date." Then I tell the customer "it is your well. if it doesn't produce enough water or has a bunch of sand, I'll work with you to fix YOUR WELL, but it will be Time and materials." So we tap the main, run the water into 5 gallon bucket. Bucket is muddy. Clean bucket out. Fill again. Still muddy. Stick hand in bucket, pull out sand. Customer walked out at that EXACT moment. Umm, sir, you have sand in your water. OH NO, that's not sand. that is MICAH. You didn't ask about Micah!!!! sigh. Sir, you need a Micah filter to make your sprinklers work.