has anyone out there had a problem with tank water siphoning into co2 supply line from internal reactor?.using airline check valves for now.when morning comes water in lines. co2 and reactors are shut off with lights.i ordered brass check valves, but i have a feeling that is not going to correct the problem. regards, cornhusker

There should not be any back pressure, simply make a loop so the line is about 2-3" higher than the water surface.
Aquamedic makes a decent check valve.

Regards,
Tom Barr

I have only had problems on a DIY setup. The water in a new bottle was warmer than the air, so when it gradually cooled it sucked the water from the tank. It eventually fixed itself when it started to produce CO2.