kalk reactor/feed tank siphon problem

[LiquidLunch]

I have a small problem with my configuration. As shown in the picture, my auto top off system feeds the reactor and there seems to be a siphon problem. After the auto topoff pump feeds water to the reactor, it siphons the water back into the RO tank on the far left. Would raising the RO feed tank reverse the situation and overflow the reactor and then the sump that it feeds? Any tips to fix this?

[LiquidLunch]

morning bump

[chandlerchris]

the way that i have my system arranged is as follows. I place my fresh R/O water in a closet about 5 feet in the air on a shelf. i just place the syphon tube in the top of the tank but make sure it is touching the bottom. next this syphon tube runs down to the Kalk stirrer on the ground. the distinction i have is that the inlet for the R/O water from the R/O storage in the closet to the kalk stirrer is in the BOTTOM of the stirrer, not the top. my top off solution (kalkwasser and R/O water) is then drawn out of the TOP of my kalk stirrer and is under syphon pressure to the float valve in my sump. so when the level drops, the syphon draws out top off solution from the stirrer which in turn draws in R/O water to keep the stirrer completely filled and under slight pressure. (i had trouble with leaks from the stirrer because of the pressure.) I believe that because the feeding syphon (the R/O water in the closet,) was so much higher in the air than the rest of the system. On the other hand, i dont have to really worry about the syphon for top off ever breaking. therefore i have a constant water level, constant salinity and constant calcium levels all in one easy to set up solution.

[LiquidLunch]

thanks for the post. i mulled over getting a $300 doser for a minute but i may try a check valve first. i found a John Guest type check valve on the net which i think will resolve my issue.