[dave.e]

Actually it should perform better than that.
Peter Fogwill once told me that those RO's should be working at 97-98% efficiency.
We use one of Peter's RO's like yours with 150gpd membranes and in the old days our water TDS was 254 and it was working at about 99% leaving us with a TDS of 3 which he advised to use as it was without polishing it off. Our water pressure is 65psi and we don't use as booster pump.
Our water quality is much better now a whole lot of pipes have been replaced (TDS of 96) and our membranes are still fine although over 4 years old.
I was once told by Ro-man when we purchased these that the best membranes to get are the American manufactured ones rather than the cheaper Chinese/Korean ones, as they perform better.

The connection diagram from Cleancare was on the Ro-man site, but the system we got from Peter wasn't connected up the way of the diagram. The Ro-man diagram shows the waste from the first membrane being used as the water supply for the second, with the second's waste being the feed for the third membrane. This means that the third membrane is having to work with water that has the reject water from the previous membranes, so won't last as long as the first one as the water passing through that membrane will have a very much higher TDS than the tap water.
Peters Ro's had a splitter after the carbon filters that divided the water into 3 and feed each membrane with the same water ie in your case 265. Then each of the pure outlets were connected together as were the 3 waste outlets. IMO this is much better, although the pipework is more complicated.

Spruce

thanks for the reply spruce i did get my system from peter and my ro,s was connected like you said without using the waste to feed the other ro,s. i to think this way is much better but i was told feeding the ro,s with the waste bring down the tds so i swapped them back and got a higher tds of 23. so what do you think is better

                                                                           1/  waste feed from 1 ro to the other or
                                                                            2/     done with the splitter and feed them individually


                                                        i would have said 2 but the tds is higher. Dave

[mikecam]

. so what do you think is better

                                                                           1/  waste feed from 1 ro to the other or
                                                                            2/     done with the splitter and feed them individually


                                                        i would have said 2 but the tds is higher. Dave

If you are getting a higher TDS reading when they are fed individually then i would suspect one faulty membrane. See if you can get a reading from the membranes individually.

[Frankybadboy]

dave i have the same system as you my tap tds is 380 and i run with a booster pump at 105psi

and it get it down to 6 but some days 4s.

then though di to poilsh off to 0.

iam more happier with it at 0 before anyone says.

my system is pump up like the one you posted.doing the way like spruce say i couldnt get pressure to last memebrain an didnt have time to mess about.so left as it was.

so many cheap memebrainsgoing around,that dont work as good as the originals

[Spruce]

. so what do you think is better

                                                                           1/  waste feed from 1 ro to the other or
                                                                            2/     done with the splitter and feed them individually


                                                        i would have said 2 but the tds is higher. Dave

If you are getting a higher TDS reading when they are fed individually then i would suspect one faulty membrane. See if you can get a reading from the membranes individually.

Sorry to have not replied earlier.

I agree with Dave. I would connect each RO membrane separately and check the performance of each one over a period of time, say half an hour. I would also suspect that 1 of the membranes or seals are faulty/not seated correctly allowing water contamination. If one of the membranes shows a higher TDS reading than the others then this could be your problem one. I would then reassemble that membrane very carefully, using a very thin layer of silicone grease around the 2 rubber o rings on the main shaft (I have also used a tiny bit of fairy liquid with no adverse effects). Also I would make sure that the housing is nice and clean - no dirt or grit so ensure that the outer rubber seal on the membrane can make a clean seal to the housing.

Spruce