WRO300H Membrane Cleaning

[Matt Waite]

Does any else routinely clean their single patient RO membranes?

Ours are heat cycled regularly, and chemically sanistised in the event of a poor microbiological sample result.

As part of a 12 month service the membrane is acid / alkali cleaned. Additionally they're citric cleaned 3 monthly if fed from unsoftened water. This regime means we typically get 5+ years from a membrane.

Our usual supplier has let us down with chemicals. Can anyone recommend anything? Or is cleaning not cost effective? Should we just diolox as-and-when and see how long the membranes last?

[Ian Wilde]

Hi Matt,

What we do at its suits our home programme size and staffing level is to chemically disinfect every 6 months and that's it.

Our incoming water is soft at ~60ppm so we don't use softeners.  We do get some reduction of flow some times but at that point we swap the RO out and give it an overnight citric soak which usually recovers it.

We're 95% on the Aqua Uno cold disinfection model so couldn't heat if we wanted to.  I wouldn't say we get as long as you out of a membrane however I suspect that is more to do with chlorine damage due to patients not changing filters when they should. Membranes for the Aqua Uno Cold can be sources for around £350 so not too bad.  I believe the Aqua Uno Hot membranes are about £2k though.  I have no experience on the WRO300H unfortunately.

We have also stopped testing for micro now on home patient RO units backed up by considerable historical data. Some may say that's controversial however when you're changing diasafe filters evert 3 months and only obliged to test every 6 months anyway any sample is only as good as the moment it's taken.  Symptoms from a micro infection certainly wouldn't take 6 months to present themselves.

You don't have to sample fluid produced by the NxStage device and the PAK in that is also changed every 3 months like the diasafes/ultrafilters on most machines.

[Garry]

Hi Matt,

We only have WRO300Hs running on softened supply at one of our units.  Weekly heat disinfection and an annual citric acid.  When we have seen microbiological issues it has been towards the end of the membrane life where attempts to disinfect (heat and chemical) did not resolve for us - new membranes fixed them all.  We have been following this process for over 14 years. ROs lifecylced a few years ago.

Not that likely impacts on RO performance but we also perform a weekly low flow in heat with the RO as well.

[Chris Bates]

Hi all,
Just ordered a couple of Aqua C Uno H membranes. Never actually had to replace one yet but some of ours are getting a bit old.
There is a new part number - F40018643 - MEMBRANE AQUA C UNO H now less than a third of the old price !

[Ian Wilde]

You got the tools to get it out Chris? We changed one recently- was a bit of a faff compared to the cold Uno.

[Ian Wilde]

Also, was the old price about £2k???

[Chris Bates]

Yes, the old price was a snip at about £2k

We're just going to have to put up with the faff - the tools are also completely ridiculous prices.

We have removed end caps from housings very easily, on other ROs, just by pressurising the housing with a pump made from a 50ml syringe and a couple of check valves. Works very well,