My pool thing was installed 13 years ago and the cartridge went bad because the previous owner did not read how to take care of it. After making some inquires Alan Auerbach contacted me (found the original installation records) and troubleshot the problem in an email. We talked and ordered the new cartridge and he offered a free service call if that wasn't the problem. He even hand delivered it to my office and gave me his cell phone if I needed help installing.
Install was easy and system works as advertised. Not more chlorine tabs!
Outstanding product and even better customer service!