I think he had a point there its always better to go direct to be safe.I called http://www.freshwatersystems.com/pr.../1228/None/None
They have 31 in stock (they said they can go in one shot) there $21.56 each + $2 handling + $8.53 shipping, So 17 meters is $22.17
Then i called the company http://www.tdsmeter.com/products/dualtdsmeter.html
For 10+ is $22.00 each meter + $8.00 shipping.
So thats $22.47 each meter They have a lot in stock, for 30? more i think we should go with them. If everyone agrees i can give my PayPal address,