Clogged Injector in Iron Filter

Customer writes:

Thanks for your help.  The problem is described in detail below, but the short version is that I couldn't get the Potassium Permanganate to draw during the regeneration cycle, even after I checked the injection valves.   Your advice was essentially, "check them again, because they're the problem 99% of the time".  So I did, and you were right.  I'm writing this email to give you some feedback which may help others.

 

The green sand system - when I first checked the injection valve, it appeared clear.  I could see a nice round hole.   BUT, I didn't suspect that although I could see a hole, that it should have been Bigger.  When I inspected the second time, I again saw the hole, but used probe to scrape the walls and found a uniform crusty buildup.  When cleaned, the hole was twice the diameter!  It now draws fine.