[Avo]

Something worth a try for you guys..

Last year my 4040 tds started going up and it reached an all time high of 57tds from 450tds so I thought ok time to buy a new one.. being a Friday I had the weekend  to take out the membrane and thought ok it's going in the bin.... so before I do I'll run some big k cleaner inside it and flush it and see what would happened, unbelievably the readings went from 57 to 18 just from spending £3.99.  Yesterday did the same thing tds had reached 38 put some cleaner through it and dropped it to 22..
My point being if your about to bin your membrane because of high readings give it ago first it might save you £250

[richard groves]

Thanks very much Avo for posting that. One of the most useful tips I have read on here in quite a while.
 

[Avo]

I'm not suggesting to run it unless you have to though as I've only tested mine in the van

Works though 

[richard groves]

I take it you mean big K as in the descaler ? ( just googled it )
How did you use it ?
I mean did you remove membrane and immerse it neat or diluted or actually pump it through the membrane within the housing and just connect up to tap and flush after ?
I no longer use my 4040 at the moment ( buy my water due to present circumstances ) but when I did I would be changing the membrane every 18 months to two years due to not being able to boost it . This sounds like a good idea for someone in my position who would otherwise be throwing the membrane in the bin.
Sure I have also read in the past somewhere of a solution that you can buy to revive the performance of an ro membrane ?

[Avo]

First time I took it out but yesterday left it in... filled my marolex 5 litre pump sprayer and fed it in with pole hose and left for 5 minutes before flushing 1 hour, I parked half on the kerb outside my house to tilt the ro slightly..
I diluted the k just over half a bottle into the sprayer..

Thanks rob

[Small but perfectley formed]

You can clean ROs  need acid cleaner for calcium then a alkaline for bio film you can  buy these  specially for RO membranes but from my research only large amounts.

[Flash..]

I have never tried it in a 4040 but Lidl do a descaler that is better than any I have tried.

[a900]

So my membrane was giving out 30-32 tds at around 70-80psi. So I thought fairly knackered. Nothing to loose giving this a try. I used gardeners recommended b&q kilrock descaler. First time it dropped to around 26. So I knew I was on to something so I tried it again with much less water removing the prefilters and pumping it directly though the membrane in a few litres of 0 tds filtered water

Now I'm getting 17. So I would very much say this is worth a try lads. £3 something is much less than a 4040 membrane.

[swanson]

Great post
Very helpful

[Walter Mitty]

I guess I've been very lucky with my HF5 so far.  I've had it 4 or 5 years and it's consistently turning water out at 008 once it settles after start-up.  Pressure is 35-40psi.  I do run with waste on full for maybe 15 minutes a week.  Tap TDS is around 200.