I finally added a flush tank for the purpose of flushing out the system with fresh water at the end of the day. Previously I would transfer the draw tube from the chemical tank to a 7 gallon container of fresh water and flush the system out by spraying back into the 7 gallon container. Now I added a 35 gallon tank for fresh water, removed the draw tube from the chemical tank and instead connected the pump inlet to the chemical bulk head and added two valves. I also installed an in-line filter. So now to flush, I close the chemical valve, open the fresh water valve and spray into the fresh water tank. At the beginning of the next day, I pump the used flush water into the chemical tank and replace it with fresh water ready for the next flushing.
Having fresh water readily available is always a good thing. A small check valve wouldnt hurt. Especially if you have employees. Those ball valves get tight after a while and you think you closed it all the way but not. Then someone will go rinsing landscape or something and boom, you're fuked.
Great advice Ed! And those ball valves are desert for SH. I went from a draw tube to an all ball valve set-up with two 65 gallon leg tanks... all Schedule 40 material (white) and the ball valves failed within 4 weeks. I then cut out all the SCH 40 and replaced it with SCH 80 (grey) but still had issues with the ball leaking after a few months and switched back to a draw system.