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adamangler

R.O problem - can you bleach them out ?



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adamangler

Hi chaps.

 

Having a problem with my 450 gpd r.o that the tds wont go down on.

 

About a year ago i upgraded from a 150 to 450 r.o put new membranes in all was fine.

 

Anyway about 3 months ago tds was getting up to about 40 so i ordered some cheap membranes off ebay and sediment and carbon filters. Changed it all over but the tds was about the same, around 30-40. I was a bit gutted and put it down to the cheap membranes (voltron).

 

So fast forward to last week and the tds had gone up to 50...so i ordered some axeon membranes from @doug atkinson they came today...i put them in with new sediment and carbon filter, flushed it, ran it for a bit etc....tds wouldnt come down below 50

 

so now im a bit perplexed, i checked each membrane one by one by by-passing the others to see if one was the problem.... nope. i took the carbon and sediment filters out, nope still same.

 

I noticed when i by passed the last resin cartiridge the tds dropped slightly, but the resin chamber is empty and all clean inside.

 

SO i took each mebrane and housing off and run it direct to the outside tap and after a quick run they were coming out at 12 tds (from 280 tap)

 

put them all back on the r.o and tds back up to about 50.....

 

SO (lol) the only thing i can think of is the housings, pipes etc are contaminated ? is this possible to affect tds like this ? if so how do i clean it, run a load of bleach through ? any other ideas anyone ?

 

@spruce any ideas ? 

 

thanks

 

Edited by adamangler

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AGlassAct

Some membranes need AT LEAST a couple of hours to settle. Give them chance to bed in and see what the TDS is then. I’ve never heard of housings getting contaminated to the extremes your talking about but I did read on one of my pre filter housings they recommend you renew the ‘bowl’ portion every two years - so it must happen. Doug will have the answer I’m sure!!


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adamangler

Ive bought 2 lots of membranes now and had the same thing, both times when changed the tds is about 30-50 even after days/weeks

 

never had this before, just wondered if its getting old, if cleaning it doesnt work ill have to buy a complete new one 

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doug atkinson

Hold the pure and the waste water pipes side by side. Does the waste water flow longer than the pure water?

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adamangler
4 minutes ago, doug atkinson said:

Hold the pure and the waste water pipes side by side. Does the waste water flow longer than the pure water?

 

ive played around with the pure waste ratio doug, i use a tap to alter the ratio, it doesnt seem to make a difference.  i had it set at 50/50 when my tap tds was 150, now i have it set at 70 waste 30 pure, but ive tried all sorts of ratios and the same i cant get it below about 30 at best

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doug atkinson

Okay try and measure each membrane what the output ppm is. You probably may have some contamination somewhere. measure the ppm after filters.

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Iron Giant

Have you also changed your pre-filters for good quality ones as the cheap membranes will have had a negative impact on the pre-filters, I had R/O issues a while back and new membranes and new pre-filters did the trick.

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adamangler

There must be something contaminated somewhere as as a last resort i have taken 1 membrane and housing off and connected it straight to outside tap, set the pure/waste to about 60/40 with a tap on the waste outlet and im getting 16 tds (3 months old voltron membrane)

 

i will use it like this until the weekend then strip the whole thing down and check pure tds after each membrane etc.

 

thanks for your help

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Skxawng

I don't know any normal reason why the readings should be that high. The only thing I can think of is that you may have mixed up the output pipes on one of the membranes (I assume you have 3) so the waste from one is going to join the pure from the other two membranes and the pure output is going to the waste.

 

I've a similar problem but not as extreme- Just bought 3 new Axeon membranes and after a day of running they're producing 13ppm with 313 input. That's only 95.8% which is disappointing seen as they're supposed to be 98%.

 

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doug atkinson

What I have noticed recently with Axeon membranes it’s taking a lot longer to get our test results. Could normally achieve it in 2/3 hours now it’s taking around 10/12 continuous flushing.

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adamangler
Just now, doug atkinson said:

What I have noticed recently with Axeon membranes it’s taking a lot longer to get our test results. Could normally achieve it in 2/3 hours now it’s taking around 10/12 continuous flushing.

 

So what's the best practice with new membranes Doug? Flush first ?if so how long for ? Thanks

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doug atkinson

I’m finding at least 13+ hours before I can get them to an acceptable level now. They seem to hang around 95% and drop slowly. Before couple of hours and would get 98%. To flush them yourself takes time so would say flush couple of hours run whatever you need then flus again. In your case something is restricting the membranes

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Green Pro Clean Ltd

Not my chosen area but many lads have said with drought like conditions of late their input TDS is through the roof. Could this be to blame?  

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LAMS

Have you tried adding a booster pump so your RO is running at a higher pressure?

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Dave B

I had this problem last year with axeon from Doug 

After a 4 hr flush it stopped going any lower but after a weeks use it had settled down to 11ppm from 340ppm in so was happy with that

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Den

I bought some axeon membranes from another supplier Wrekin water and had to send back after a few days producing and flushing the tds was really high and just didn't drop resorted to putting My old ones back in and performed much better than the Axeon membranes.

Im going to buy some new membranes in the next few weeks so watching this thread. 

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Skxawng
On 28/08/2018 at 23:10, doug atkinson said:

I’m finding at least 13+ hours before I can get them to an acceptable level now. They seem to hang around 95% and drop slowly. Before couple of hours and would get 98%. To flush them yourself takes time so would say flush couple of hours run whatever you need then flus again. In your case something is restricting the membranes

I think it can be even longer.

As mentioned earlier, I bought 3 Axeon membranes and after a day they were running at 95.8% efficiency which I was unhappy with. Yesterday they had reached 97%. Today I checked and 6ppm with 297 tap. So that's finally the promised 98% but it took 3 days! 

How long did you give yours @Den?

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Den

Mine didn’t drop after approx 4/5 solid days of continuous running and flushing my tds was approx 270 couldn’t get below 20 even running membranes at 4 waste to1 pure my son had keep the old membranes in water so stuck them back in and tds went back down again my membranes are currently running approx 95% so want to change them soon but got to admit the Axeon from Wrekin water put me off tbh as wasn’t sure if they were original or copies,. I test all three membranes individually and all three were exact same days later. 

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Skxawng
55 minutes ago, Den said:

Mine didn’t drop after approx 4/5 solid days of continuous running and flushing my tds was approx 270 couldn’t get below 20 even running membranes at 4 waste to1 pure my son had keep the old membranes in water so stuck them back in and tds went back down again my membranes are currently running approx 95% so want to change them soon but got to admit the Axeon from Wrekin water put me off tbh as wasn’t sure if they were original or copies,. I test all three membranes individually and all three were exact same days later. 

Definitely sounds like they were faulty then. Funnily enough I was thinking the same thing about them being copies as I bought mine from Wrekin water also but it's funny how all three of mine have settled at 6ppm and your three couldn't get below 20ppm with similar tap TDs.

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trevor peacock

Just bought 3 from wrekin as doug is out of stock.

They seem fine, 330 in, 7 out. They've been running all day and seem fine so far.

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Den

Glad to hear you guys had more success than me, mine was doing my nut in 😡someone did look at the serial numbers and it could be not saying it true that they made have been old stock so maybe that was the problem. 

 

What’s your water pressure guys mine is approx 70psi.

 

i was getting 006-007  tds front approx 300 from my original membranes for a couple of years before they started to deteriorate. 

17 minutes ago, trevor peacock said:

Just bought 3 from wrekin as doug is out of stock.

They seem fine, 330 in, 7 out. They've been running all day and seem fine so far.

How long before yours settled down mate.

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trevor peacock

I’ve got a booster pump and run at 80psi. 

I changed the three prefilters for a fibredyne and a sediment filter at the same time. 

I flushed for about 15 minutes and got 08 from 330 then onwards. 

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Den
7 minutes ago, trevor peacock said:

I’ve got a booster pump and run at 80psi. 

I changed the three prefilters for a fibredyne and a sediment filter at the same time. 

I flushed for about 15 minutes and got 08 from 330 then onwards. 

Yes I use fiberdyne also Fortunately My water pressure is good so don’t need a booster. 

Wished it turned out for me going to try the Axeon again but will get mine from Doug this time. 

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Skxawng
1 hour ago, Den said:

 😡

What’s your water pressure guys mine is approx 70psi.

Mine is only 48psi, maybe why it took so long to reach the 98%. It's unlucky you've ended up with a bad batch- unless there is some other issue with your system but I can't think what.

Edited by Skxawng

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Den
24 minutes ago, Skxawng said:

Mine is only 48psi, maybe why it took so long to reach the 98%. It's unlucky you've ended up with a bad batch- unless there is some other issue with your system but I can't think what.

No all working as it should I did order and fit another flow restrictor just in case it was that, all the serial number were almost the same so was from the same batch.

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