[MikeyL]

I have just bought a new membrane and need some detailed fitting instructions please. I fitted the original membrane but it didn't last very long, now can't find the instructions and i've heard that it has to be the right way round but i'm not to sure which way is the right way.
I have also tried ringing Gaps but no answer. Any help will be much appreciated.
Mike

[[GQC] Tim]

Hi Mike. There should be a white rubber flange/ring on one end of the membrane. That end goes in last. That is where the inlet is. So the cap with one barb goes on that end. The water pressure makes that ring expand, sealing it so no tap water can go past the membrane.

Make sure you properly disinfect the whole housing and then rinse. Make sure no biological growth can happen.

How long did your original membrane last? How often did you change pre-filters?

How old is the housing?

[MikeyL]

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

[[GQC] Tim]

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.

[MikeyL]

Thanks for your feed back Tim very informative. I have the RO running like a dream now, thanks for the info on the pre-filters I think I need to change them more frequently.
Mike

[Lee GLS]

Tim, how do you get your pre filters to seat properly? When I changed mine this time the sediment filter was crushed at the top where it didn't locate properly in the filter housing top.

[[GQC] Tim]

Tim, how do you get your pre filters to seat properly? When I changed mine this time the sediment filter was crushed at the top where it didn't locate properly in the filter housing top.

Not sure which housing you have, I've got some 1/2" ones from Gaps, I don't seem to have any problems. There is a small circle indent in the top of the sediment filter but that's it?

[[GQC] Tim]

Oh ps. it's best to flush it for 10 min or so before every fill. At the end of the week I usually have a 20 min flush. Regular flushing is more important then one long flush at the end of the week.