Are you saying that you've had the same pre-filters installed for a year? If so, that's likely the problem - the membrane wrecked due to pre-filters not being changed frequently enough.
I change the sediment and carbon pre-filters three time a year, though occasionally it goes to five months. These are 20". If using 10" ones, they will need a more frequent change. I'm a sole trader. I have low water pressure (35-40 PSI). I use the low pressure 4040. I do not use a booster pump. I turn waste on full flow for a minimum of 15 minutes per week, sometimes twice per week. So far, the membrane has lasted about 5 years. TDS 200 in, 008-012 out, depending whether or not I allow plenty of waste. The only down side is that the pure has lowish production for such a membrane, but it's plenty for me (60 - 100 litres of pure per hour).