The history of my old 150 gallon Tenecor and sump is as follows:
Set it up spring 2006, used it for 6 months with sump, then I took it apart; tank remained apart for one year, then was set up again for one year, but without sump (Kenta called it a leak factory
). I finally got around to setting up the sump again last month and it is working great. I have never cleaned out the flow valve/ball valve, but then again I have used the equipment so little that I wouldn't know whether it will eventually need cleaning,
Here is a photo of the tank when I first got it: