I have a practically new Tunze Osmolator 3155. It was purchased the end of March and was only used for about a month and a half. I have the original receipt. I also have an XP Aqua Ultimate ATO that's about a year old, comes with an electronic solenoid valve. Its in great condition. Selling the Tunze for $125 and the XP Aqua for $80. They both retail for $199 each. PM or text please.