Don't know if this is the right forum to post this but here goes. I have an automatic water change system in the basement route up to my 90 gal tank on the first floor using the Apex DOS. I also have a separate reservior in the basement for collecting RO/DI water from my water system. Here's the problem. I want to use the RO/DI tank to top off my sump under the tank. I tried using a PMUP but the head pressure was too much. Someone suggested a peristaltic pump. I had a used flex-master that I set up next to the tank and tried into the Apex ATO system. This has not been very successful. The master flex will not turn on when the watew level drops below the first sensor. I can manually turn it on with my apex app and the water slowly comes into the sump but when I set the apex app to auto for the ATK pump it immediately doesn't stay on auto but goes to off. Is there a better way to top off my sump from a basement reservior? Thanks