JBJ Auto-Topoff Questions

[bronck83]

Recently hooked up a JBJ topoff system. I bought it used & thus have no instructions. It seems to be working fine but I have some questions as this is my first auto topoff unit...

1. It came with 2 float sensors, I figured 1 was for "off", 2nd was for "on" so I set them at different heights. But it seems to only operate on the higher up one which makes the 2nd one(lower) seem useless. Am I doing something wrong here?

2. What is the switch on the side of it for that slides up & down?

3. Is there a way to disable the internal speaker?

[BioCube14]

hmm you have the old model not sure how to turn off sound

[ErikH]

Change the heights. One is set as a backup to make sure you do not overflow your system, in case the first one gets stuck. The speaker is to let you know it's on and for what duration. I use my ATO for my water changes, and it will usually only do 5 gallons.