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5 stage RO system help

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First of all Thank you all for the great info anyone can find here.

I've read several posts about setting up my RO, but im finding it difficult to how to set the waste valve.

Your hell would be very much appreciated!

 

07/12/19

new Axeon HI5 4021 membrane.(flashed for 2 hours)
New 11L resin.

New 20" sed/carb

Booster pump bought from Daqua.

 

Water tap ppm 370 ( -_-)

Ppm using booster pump
Pure without resin 23ppm at 90psi, ratio 60%pure 40% waste.
Pure without resin 20ppm at 50psi, ratio 50%pure %50waste.

 

Ppm without booster pump
Pure without resin 33ppm 20psi 60% pure 40%waste
Pure without resin 30ppm 10psi 50%pure 50%waste, no water comes out.

 

I know for what I've read that I should never fully close the waste valve not to ruin the membrane, hope Im right...

I dont mind using the booster pump to get the lowest ppm as possible but how do I find out how well this membrane is working?

Is 20ppm to high to go through the DI vessel?

 

Thank you for all your help 

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Iron Giant

20ppm isn't to high to go through a DI vessel, but depending on how water you need you could well find you will eat through the resin quickly with only using a small DI vessel, @spruce is well informed on these things or the other lads who have a similar set up will chip in

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Martyn

How quickly after turning on the tap are you measuring the TDS? It can take a few minutes to settle down to it's lowest level. I would have expected single figures TBH but I use a 4040 so maybe I'm spoiled.

 

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spruce

At your tap water tds of 370 you would be better at a ratio of 60 waste to 40 pure and working from there.

 

Our water is 150ppm atm and our ratio is best at around a ratio 55 waste to 45 pure.

 

You have already seen a difference of pure output (23 to 20) using a higher waste output.

 

Yes, you must never fully close the waste output when running the r/o.

 

Lets tackle the big question. How do you know how well the membrane is working?

In other words, how efficiently its working at removing dissolved solids from your tap water.

We always say a membrane should remove between 97 and 98% of the dissolved solids from your water. The remaining 2 to 3% will be removed, or polished off by the resin.

 

According to the calculation your pure should read between 7 to 9ppm after r/o and before the di vessel.

 

At 23ppm your r/o is running at 94% efficiency.

Firstly you need to get the waste up and then let the r/o membrane settle down.

 

@Martyn makes a good point. You need to let the r/o run for around 5 minutes before you take readings.

Edited by spruce

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doug atkinson

Have you flushed the membrane, all to waste for at least 4 hours to get a decent rejection rate

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Guest
2 hours ago, spruce said:

At your tap water tds of 370 you would be better at a ratio of 60 waste to 40 pure and working from there.

 

Our water is 150ppm atm and our ratio is best at around a ratio 55 waste to 45 pure.

 

You have already seen a difference of pure output (23 to 20) using a higher waste output.

 

Yes, you must never fully close the waste output when running the r/o.

 

Lets tackle the big question. How do you know how well the membrane is working?

In other words, how efficiently its working at removing dissolved solids from your tap water.

We always say a membrane should remove between 97 and 98% of the dissolved solids from your water. The remaining 2 to 3% will be removed, or polished off by the resin.

 

According to the calculation your pure should read between 7 to 9ppm after r/o and before the di vessel.

 

At 23ppm your r/o is running at 94% efficiency.

Firstly you need to get the waste up and then let the r/o membrane settle down.

 

@Martyn makes a good point. You need to let the r/o run for around 5 minutes before you take readings.

Thank you for your help.

Yes I do leave it to settle for t least 5min.

Now at %40pure %60waste and booster pump and settle for over 10min it reads 65ppm.

I think Ill have to stick to %50 %50... to get 20ppm.

 

Thank you 

25 minutes ago, doug atkinson said:

Have you flushed the membrane, all to waste for at least 4 hours to get a decent rejection rate

 

I flushed it for 2 hours, do you think I should flash it again for 4 hours to see better ppm?

 

Thank you for your help.

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spruce
35 minutes ago, Lucas said:

Thank you for your help.

Yes I do leave it to settle for t least 5min.

Now at %40pure %60waste and booster pump and settle for over 10min it reads 65ppm.

I think Ill have to stick to %50 %50... to get 20ppm.

 

Thank you 

 

I flushed it for 2 hours, do you think I should flash it again for 4 hours to see better ppm?

 

Thank you for your help.

 

Now I'm confused as it shouldn't have gone up like that.

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Guest
7 minutes ago, spruce said:

 

Now I'm confused as it shouldn't have gone up like that.

After tweaking several times this is my best option to get the lowest ppm 20.

 

Thank you Spruce

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Hoops

Hi guys, 

 

I have a 5 stage fixed pure water system in my garage. I run the water off the mains which then goes through a 20” sediment filter - 20” carbon filter - 11L water softener resin vessel - 4040 RO membrane - 11L DI resin vessel and then into a fixed IBC container in my shed. I then pump my water into my vans. 

 

I had this set up around 8 months ago and due to not being educated in any of the upkeep procedures I just used the water until I saw it creep up in TDS levels. I flushed the RO upon receiving it but never felt the need to for months as I was getting low TDS readings.

 

TDS recently creeped up to around 009 ish so I then got another local windee to run me through everything. He is saying that I should be flushing the RO out once a week as well as give the water softener resin a salt backwash (which is fitted on the system). I understand that the system needs far more upkeep than I was giving it but with the levels I was getting for months and months surely doing these once a week is a little excessive? 

 

When my levels crept up my production nearly came to a stand still so i flushed the RO, salt backwashed the water softener and changed the DI resin out too. I now have the TDS back down to 000 and production is back to where it was. 

 

So can anyone give me rough guidelines on how to get the best out of my system and make filters and resins last as long as they can? I only use around 1000 litres of product water a week! 

 

Thanks

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Martyn

You should salt backwash every time you fill the tank, I confess that I no longer do it that often. You should also flush the membrane regularly but you are only producing a very small amount of water so maybe once a month?

The other filters will also need changing from time to time.

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Hoops
2 minutes ago, Martyn said:

You should salt backwash every time you fill the tank, I confess that I no longer do it that often. You should also flush the membrane regularly but you are only producing a very small amount of water so maybe once a month?

The other filters will also need changing from time to time.

So you think I’ll get full life out of salt backwashing and flushing once a month? The carbon/sediment filters I’ve been told to change every 150,000 litres of water I put through them. How do I know when to change my DI resin? 

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Martyn

I wouldn't like to say that about the salt backwash, I've gotten a bit lazy after nearly 20yrs of system maintenance.

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Dave B
1 hour ago, Martyn said:

You should salt backwash every time you fill the tank, I confess that I no longer do it that often. You should also flush the membrane regularly but you are only producing a very small amount of water so maybe once a month?

The other filters will also need changing from time to time.

That is for water softeners.

Salt makes no difference to ro's.

I connect my booster pump to my van tank full of pure once a month and put the ro on full waste to flush it and after 5 to 10 minutes the tds of the waste drops to 0ppm and then I know it is clean and then use for another month.

The salt makes absolutely no difference  unless it's a water softener you are cleaning.

I also flush for 5 minutes every day before producing water.

Edited by Dave B

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spruce
1 hour ago, Hoops said:

So you think I’ll get full life out of salt backwashing and flushing once a month? The carbon/sediment filters I’ve been told to change every 150,000 litres of water I put through them. How do I know when to change my DI resin? 

 

Everyone you talk to will have a different opinion as to when to change prefilters.

 

One of the suppliers will tell you that tests have shown that there is very little chlorine in your tap water. The further you are away from the dosing station the weaker the chlorine content of the water will be. I have no reason to question that advice as it comes from a reputable source and a person I have a lot of respect for.

I will also say that we haven't experienced a smell of chlorine in our tap water for a long time according to my wife's nose. (Mine is unreliable I'm told - like everything else - but that's another story. 😂)

 

This is an interesting read.

https://www.cdc.gov/safewater/chlorine-residual-testing.html

 

The reason for the carbon block filter is to remove chlorine from the water as chlorine and membrane material aren't good bedfellows.

 

If there is no chlorine in the water then you wouldn't need a carbon block filter. This chlorine dosing is a specialist operation and by all intense and purposes works very well.

 

My reasoning is that you don't know exactly how much chlorine is in your water at anytime. Since I've run my 4040 I have chosen to replace the 20" Fiberdyne c/b filter to the manufacturer's recommendations. For this filter its +- every 76k. I have my r/o on a water meter so can determine when to replace this filter. It could be that I'm wasting money as it would probably be fine for 150k. I just don't know.

The next question I ask is how do the manufacturer's know how often I need to replace my carbon block filter? They don't, so they would have to assume the maximum chlorine content in your water for it to be potable.

 

A 4040 HF5 Axeon membrane is expensive to replace. By following these instructions my r/o is still working at 97% efficiency after more than 6 years. So I will stick with my replacement routine. There are window cleaners who have not replaced their c/b filters for a year or 2 with no issues. They will tell us that I have spend and wasted £135 a year on carbon filters.

 

The sediment filter is there to protect the carbon block filter. We go through periods where our water is laden with sediment. There were times when I could replace the sediment filter once a month and the c/b filter once every 3 months - that's how bad our water can be.

 

When to change resin is another question.

For us I don't like to see the water coming out of the di vessel going above 1ppm. Some say 5ppm others say they can clean windows with 10ppm and be fine.

At 5ppm I can see small white deposits on our lounge window in low sunlight. I tested this with a back pack with pure water adding a touch of tap water to get the desire tds of the water in the backpack.

 

I don't know much about water softeners. But I do know that they remove metals in the water such as calcium and magnesium ions and replace these with sodium ions. Sodium ions are much more gentle on r/o membranes. The before and after tds of water through a water softener won't change much if any.

 

 

 

 

Edited by spruce

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Hoops
15 minutes ago, spruce said:

 

Everyone you talk to will have a different opinion as to when to change prefilters.

 

One of the suppliers will tell you that tests have shown that there is very little chlorine in your tap water. The further you are away from the dosing station the weaker the chlorine content of the water will be. I have no reason to question that advice as it comes from a reputable source and a person I have a lot of respect for.

I will also say that we haven't experienced a smell of chlorine in our tap water for a long time according to my wife's nose. (Mine is unreliable I'm told - like everything else - but that's another story. 😂)

 

This is an interesting read.

https://www.cdc.gov/safewater/chlorine-residual-testing.html

 

The reason for the carbon block filter is to remove chlorine from the water as chlorine and membrane material aren't good bedfellows.

 

If there is no chlorine in the water then you wouldn't need a carbon block filter. This chlorine dosing is a specialist operation and by all intense and purposes works very well.

 

My reasoning is that you don't know exactly how much chlorine is in your water at anytime. Since I've run my 4040 I have chosen to replace the 20" Fiberdyne c/b filter to the manufacturer's recommendations. For this filter its +- every 76k. I have my r/o on a water meter so can determine when to replace this filter. It could be that I'm wasting money as it would probably be fine for 150k. I just don't know.

The next question I ask is how do the manufacturer's know how often I need to replace my carbon block filter? They don't, so they would have to assume the maximum chlorine content in your water for it to be potable.

 

A 4040 HF5 Axeon membrane is expensive to replace. By following these instructions my r/o is still working at 97% efficiency after more than 6 years. So I will stick with my replacement routine. There are window cleaners who have not replaced their c/b filters for a year or 2 with no issues.

 

The sediment filter is there to protect the carbon block filter. We go through periods where our water is laden with sediment. There were times when I could replace the sediment filter once a month and the c/b filter once every 3 months - that's how bad our water can be.

 

When to change resin is another question.

For us I don't like to see the water coming out of the di vessel going above 1ppm. Some say 5ppm others say they can clean windows with 10ppm and be fine.

At 5ppm I can see small white deposits on our lounge window in low sunlight. I tested this with a back pack with pure water adding a touch of tap water to get the desire tds of the water in the backpack.

 

I don't know much about water softeners. But I do know that they remove metals in the water such as calcium and magnesium ions and replace these with sodium ions. Sodium ions are much more gentle on r/o membranes. The before and after tds of water through a water softener won't change much if any.

 

 

 

 

Absolutely brilliant information there fella! Thank you so much! 

 

Seems like im gonna have to just see how it goes. I only have a cheap TDS stick meter so in the new year I’ll be looking at getting an in-line TDS meter! Where are the best places to put inline TDS meters. After pre filters? Before and after RO? After DI? 

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spruce

I have a normal tds meter as well as an inline one.

 

The first sensor is on the pure after r/o and the second is after the di vessel before it goes off to storage.

 

I know my water tds can range from 79ppm to 150ppm, depending on the source of supply. If the water board is drawing water from one of the local reservoirs then the tds will be higher than if they are using water from Kilder dam.

 My first check is usually the pure water after r/o. If it reads 3 then I just assume all is well. If it creeps up to 4 then I need to fractional adjust my waste gate a bit to get it back to 3. If I can't achieve 3 then I usually get my TDS tester pen out and check the tds of the tap water.

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Pjj
On 09/12/2019 at 19:36, doug atkinson said:

Have you flushed the membrane, all to waste for at least 4 hours to get a decent rejection rate

 

 

Hi Doug can you explain why it’s nessasary to flush a new membrane for so long to get it to work efficiently please  

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doug atkinson

Sorry guys I’m on holiday and trying to relax. Lucas has sent email but Lucus has emailed us about couple of issues. I can see his set up and can see things which are wrong and could damage his membrane. This forum is great with good advise with likes of Spruce etc.. Can I please ask members on this forum please try and not listen to the FB crowd who often give wrong advise. One customer has spent £600 + and I finally twigged the problem.

 

Flushing is key as it dislodges the solids that build up in your membrane.

 

Setting the correct ratio waste to pure is key as it will damage your membrane. Then that’s money down the drain . It’s not the manufacturer fault as they have guidelines but if you listen to some people     you’ve just been wasted your money.

 

Sorry having a rant but you have to listen to specifications.

 

I am chilling out as need it but sorry some set ups are wrong and it can be very expensive wasted money.

 

If I can will help but in break which I need cheers

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Hoops
19 hours ago, Dave B said:

That is for water softeners.

Salt makes no difference to ro's.

I connect my booster pump to my van tank full of pure once a month and put the ro on full waste to flush it and after 5 to 10 minutes the tds of the waste drops to 0ppm and then I know it is clean and then use for another month.

The salt makes absolutely no difference  unless it's a water softener you are cleaning.

I also flush for 5 minutes every day before producing water.

Hi Dave, 

 

 So with my set up do you believe I’d be ok to flush the RO for about 15 mins once a month and salt backwash the water softener once a month too? Or would this not be enough maintenance? 

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