if I remember rightly it needs to be flushed for 2 hrs is this correct?
It lasted about 9 months but have now found out i had the membrane in the wrong way so i think i messed it up that way. I changed the pre filters about every 4 months if thats right?
mike
It kind of depends on the size of the pre-filter and how much water your using. 10 inch pre-filters and I'd say for a heavy user change them every month, if your going through 400l or so a day about every other month. 20 inch pre-filters last longer. But yea having it in the wrong way isn't good. Pre-filters are rated for a certain amount of liters before they get changed, and because there is a lot of waste in a 4040, you need to calculate the total amount of water going through the pre-filters, not just the product water.
Yea the membranes are coated in a special solution. If membranes dry out they get damaged. The manufacturer specs actually state to discard the product water for the first 24 hours. Definitely flush it for a couple of hours to make certain all the preservative is gone.
Also make sure you set it up to the correct ratio waste to pure. 30% pure, 70% waste. You can turn the pure up a bit, but it won't last as long. 4040s aren't great on a water meter, although they make pure water fast and high quality TDS. Use a valve on the waste outlet to adjust it.
If you need more help just let me know.