Rainbow 320 - Let's say you don't want to use it for a while


Well-known member
May 28, 2010
My thread on tablets raising CYA levels has me thinking...

Let's say that I want to minimize or temporarily not use the Rainbow 320. Obviously, I stop adding tablets to it or simply reduce the tablets. But when I'm running it empty (no tablets), is it best to just leave the flow valve all the way open? Just checking...


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
If there aren't any tablets in it, it doesn't matter where you set the flow valve. It is also alright to leave tablets in it, and turn the flow valve to zero.