I am not sure where this post best fits, so please move it to where it best fits.
Over the summer I automated my bleach addition with the use of a Stenner pump. It was a great success.
I thought it would be nice to have level indicator on the outside of my 15 gal carboy, so I got a piece of transparent 3/8" tubing. To weigh the end down in the carboy I used a piece of scrap 1/4" 316 SS tubing with a 90 degree fitting on the end which I pushed into the submerged end of the plastic tubing. The tubing was then dropped down into the bleach to fill. I plugged the other end and pulled out a loop to reach the bottom of the vessel and back up to the top again. After unplugging the end, the level on the vented end receded to match the level in the vessel. Success!
Worked fine for a few days. Then I noticed that that it wasn't working any more. I figured somehow air had gotten in and I would just have to refill the tube and start over.
I wasn't in any hurry to correct the situation so it remained like this for possibly a couple of weeks. When I finally pulled out the assembly, I found the stainless steel to be covered and plugged with black gunk. So I left it out and decided to come up with a new plan.
About this time was when 6% bleach was replaced by 8.25%. And I also got better pricing by using some 10%. What seemed to happen was even though I was increasing my chlorine strength, I was having to continually increase my injection pump time more and more to provide enough chlorination, up to an hour longer than I had previously injected 6%. Something was VERY strange.
Finally when the level in the carboy was getting close to the bottom I shined a flashlight in to discover a significant layer of black gunk in the bottom of the barrel. I dumped the last couple of gallons into a white bucket. It resembled dark black/brown muddy water. Apparently whatever the SS tubing did to the bleach hadn't stopped when I removed it from the barrel. It was still severely reducing the effectiveness of the remaining and additional bleach.
I rinsed the carboy and refilled with new 8.25% bleach and things are back to normal.
The moral of this rather long story is that chlorine bleach is very corrosive and you must be very careful about what materials you use when you automate. I think I read on a previous post that someone had installed a stainless steel valve in conjunction with a Liquidator installation. I am guessing that that was probably not a good idea.