RO Unit Help

Hi 

I bought this RO unit second hand it having had little use.

I didn't get any instructions with it but I think the guy said he bought it from Cleaning Spot in Wimbledon.

My question is do I need to go back to Cleaning Spot to get replacement filters membranes etc? 

If not can anybody identify what system/size etc it is. 

I have changed the resin several times but the tds has recently shot up from 1-2 to 8-9 not long after changing resin.

The filters have never been changed so is this why?

Sorry to sound so ignorant but any help gratefully received??? 

Thanks in advance 

Jago said:

Hi 

I bought this RO unit second hand it having had little use.

I didn't get any instructions with it but I think the guy said he bought it from Cleaning Spot in Wimbledon.

My question is do I need to go back to Cleaning Spot to get replacement filters membranes etc? 

If not can anybody identify what system/size etc it is. 

I have changed the resin several times but the tds has recently shot up from 1-2 to 8-9 not long after changing resin.

The filters have never been changed so is this why?

Sorry to sound so ignorant but any help gratefully received??? 

Thanks in advance 

View attachment 10881

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Some like me refer to them as RoMan type r/o's. The prefilters are 10" sediment and carbon block and am presuming the third housing is the resin vessel. Prefilters are 10" and are available from all good wfp suppliers.

These r/o's also come in different configurations. The photo doesn't show the pipe work very clearly so I'm guessing.

Looking at yours it appears that your first 2 housings are the prefilters. The pipe then appears to exit the second housing (which is the important carbon block filter that removes chlorine) and goes into the head of the first r/o membrane. The waste from that membrane then appears to be connected to the inlet of the second r/o membrane inlet. (The inlets are the screwed end cap end of the housing.) The waste of the second membrane then goes to the drain via what looks like a flow restrictor/flush valve.

Nobody can tell you what the 'size' of the r/o is as those housings take 50gpd, 75gpd, 100gpd and 150gpd membranes.

The way the r/o is configured means that you will save on waste water but the second membrane will fail before the first does. (The waste from the first membrane has a higher TDS than your tap water so the second membrane has to work harder than the first to remove those additional dissolved solids.)

Prefilters should be replaced regularly and depends on the amount of water you process. A Fiberdyne prefilter from Gardiners is more costly than a cheaper filter but it will remove the chlorine from 35,000 + liters of water which includes waste and pure. Most of us change prefilters every 3 to 6 months.

http://gardinerpolesystems.co.uk/all-products/pure-water-systems/water-treatment/sediment-carbon-filters/sediment-pre-filter-10.html

http://gardinerpolesystems.co.uk/all-products/pure-water-systems/water-treatment/sediment-carbon-filters/fibredyne-cfb-plus-sediment-carbon-pre-filter-10.html

(Now to confuse you even more the Fiberdyne c/b filter is also a sediment filter. If your tap water is sediment free then you can just use the fiberdyne filter alone and leave the first housing empty. Our water is full of sediment and sometimes we have to replace the sediment filter every month.)

You need to run your r/o for about 5 minutes and then take a sample of pure from the outlet of each membrane to determine if they need replacing. A new membrane should return an efficiency of around 98% and the time to consider changing membranes is when that efficiency drops to around 94%. (So a windie with a tap water tds of around 200 should expect the pure to be 3 to 4ppm. At 94% that tds will be around 12ppm. At 94% the windie will need much more resin to polish the remaining tds off.)

If you have to replace membranes then I would go for 150gpd membrane and get them from a supplier who sells membranes made in the USA and not the cheaper Chinese copies. Filmtec and Aexon are what to look for.

Gardiners sell the 100gpd membrane but not the 150.

http://gardinerpolesystems.co.uk/all-products/pure-water-systems/water-treatment/reverse-osmosis-membranes/100gpd-ro-membrane.html

Daqua sell the 150GPD membranes.

http://www.daqua.co.uk/reverseosmosis.htm

5th item down.

If the third housing is your resin vessel then my advise is to replace it with a bigger unit. 

http://gardinerpolesystems.co.uk/all-products/pure-water-systems/water-treatment/de-ionisation/7-litre-resin-bead-pressure-vessel-canister-1809.html

I like this size as its manageable when changing resin. A 25 liter bag of resin does 4 changes.

I would also order a couple of 1/4" john Guest t pieces and a meter of 1/4" tubing. I would split the water that leaves the c/b prefilter into 2 using the first JG fitting and run a feed to the second housing. I would then join the waste from the first membrane to the waste from the second membrane using the 2nd JG fitting. The wastes would be joined together before the restrictor/flush valve. This way both membranes are doing the same work.

I'm not sure exactly how that restrictor works. But depending on the tds of your water you should strive for a ratio of pure to waste of between 1 to 1 to 2 to 1 waste to pure whilst processing water.

.

@spruce i can't remember if i asked this before

By having it set up with the waste from 1 going to the next i know 1 membrane will get battered but will it produce faster as more of the waste is being forced through the membrane not out the waste so surely more pressure in the membranes

I may be wrong but just a thought

Wow thank you very much Spruce - that's very useful. 

I'll have to re read it to take it all in but I'm very grateful for your advise.

Top man 

Dave B said:

@spruce i can't remember if i asked this before

By having it set up with the waste from 1 going to the next i know 1 membrane will get battered but will it produce faster as more of the waste is being forced through the membrane not out the waste so surely more pressure in the membranes

I may be wrong but just a thought

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Its supposed to save water if you are a water meter, but honestly I can't work it out.

I honestly can't see it producing more water.

We had thread a while back on this and I asked for any comments on this issue, but none were posted. So I'm none the wiser.  My old r/o was joined up like I suggested and I kept it that way as it made sense to me.

One thing to note when changing ro membranes don't disconnected all the pipe work. Just change one by one otherwise you could end up in a right mess.

If you have not got a RO spanner to undo the end s of the ro Chambers then you will need one of those as well.

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Iron Giant said:

One thing to note when changing ro membranes don't disconnected all the pipe work. Just change one by one otherwise you could end up in a right mess.

If you have not got a RO spanner to undo the end s of the ro Chambers then you will need one of those as well.

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That's a good point @Iron Giant. Before I changed my membranes for the first time years back, I colour coded my pipes by dabbing different colour paints on each connected pipe. Still makes life easier to this day ?

steve garwood said:

That's a good point @Iron Giant. Before I changed my membranes for the first time years back, I colour coded my pipes by dabbing different colour paints on each connected pipe. Still makes life easier to this day ?

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I would likely forget half way through if I did that, Some days I get part way through cleaning a bay window and can't remember if I have cleaned the top panes of glass  :1f61c:

Iron Giant said:

I would likely forget half way through if I did that, Some days I get part way through cleaning a bay window and can't remember if I have cleaned the top panes of glass  :1f61c:

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Hey, that's me. My son says that he has never seen anyone else slip into a coma whilst cleaning windows and still remain standing up.

@spruce I am not that bad I don't think, Just got a appalling short term memory and forget all sorts I had a client text me the other week just wondering why the direct debit payment hadn't been taken from the previous clean I had forgot to re-activate the job on CP  :1f602:

Iron Giant said:

@spruce I am not that bad I don't think, Just got a appalling short term memory and forget all sorts I had a client text me the other week just wondering why the direct debit payment hadn't been taken from the previous clean I had forgot to re-activate the job on CP  :1f602:

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The problem is that cleaning windows isn't the most mentally stimulating occupation. My mind is inclined to drift onto other things non window cleaning related.

I also spend a moment going around wiping the bottom sills so also check that I haven't forgotten to clean a window. On a number of occasions I've had to get the stuff out of the van and clean a window that I had missed. For some unknown reason its never a frosted bathroom window, but usually a lounge window.

Its not only this though. I can't count the number of times I haven't locked the front door on my way out. The up side (which is also a down side) is that the parcel delivery guys check the front door if there's no van outside and put the parcel in through the front door and close it quickly before our loud barking Labrador gets there. I'm getting better at locking my van up every night though, but sometimes I forget to do it as well. 

@spruce You sound exactly like me  :1f602:  thankfully I never leave the front door unlocked just push the handle up and its locked and the women in the door handle tells me its locked.