does diy co2 ruin check valves as ive noticed after 2 weeks of diy co2 there loosing effeciancy. ie harder for co2 to get through, and easier for water to escape
have you changed the mixture recently? It might be that it is not producing as much CO2 as it was before, and nothing to do with the check valve.
I am not sure what you mean by water to escape? water wouldnt siphon back down the tube because there is a constant pressure from the CO2 being produced.