Please Help Me Fix My RO....

[Robt100]

Hey everyone, yes, another RO topic I'm afraid!

So, the background:

Bought a 2nd hand 4021 system (don't worry, I can see all you sitting there with your face in your hands ?) on ebay. It's the Daqua 4021. It's on a Van mount setup for the Wife's window cleaning (yep, not me, I'm just the brains that does the research that gets ignored....).
Tap pressure is 60psi, flow 13lpm, quality 400ppm TDS.

Now, the problem, Water after RO and DI is coming out at 8ppm at best no matter what the ratio. Partly this will be down to the fact that against my (and daqua's) advice, my wife is using a tiny 700ml DI canister to keep it "light". BUT, the RO by itself is not working correctly, pure end of the RO is reading 43ppm TDS, so only a 90% efficiency. I've also noticed that the gate valve/waste tap, even when fully closed still is on a 45waste/55pure ratio and does feel notchy, I assume this is knackered and adding to my problems? I also assume that the Membrane is done for, and that a booster would help, but not to the point where the TDS will drop into the teens just due to being at 80psi rather than 60psi in the RO?

OK, so I could just buy a nice big DI vessel and get the TDS down to 0, but id be eating the resin like nobodys business!
Is this a new membrane job and hope for the best? OR buy a new RO system and keep/sell the other for spares? Could it just be that its using an HF4 membrane rather than an HF5 and the booster WOULD solve it?
Any hints/tips/help is much appreciated, I'm new to all this and having to try and fix all the things that were done wrong to start with.....

Even if the answer seems obvious, I will need it all spelt out to me, Initiative never has been my strong point!

 

[Clisty1989]

@doug atkinson or @spruce are the ones to speak to

 

[doug atkinson]

How long does it take to do 1 litre pure when set at 55% waste 45 % pure. The 700ml DI is not fit for purpose

 

[Robt100]

Hi @doug atkinson just did a quick check, stopwatch says 30 seconds, which seems a bit fast? ? not going to be able to do much fine tuning on the ratio tonight as its now pitch black outside! But had set it around 55/45 earlier when I started filling the tank.

As for the not fit for purpose, tried telling them that..."i use it on mine and its fine" says windy friend. But hes running 300GPD, not 1000!

 

[doug atkinson]

Changing the membrane would improve the ppm but you still need a larger Di vessel

 

[spruce]

Hey everyone, yes, another RO topic I'm afraid!

So, the background:

Bought a 2nd hand 4021 system (don't worry, I can see all you sitting there with your face in your hands ?) on ebay. It's the Daqua 4021. It's on a Van mount setup for the Wife's window cleaning (yep, not me, I'm just the brains that does the research that gets ignored....).
Tap pressure is 60psi, flow 13lpm, quality 400ppm TDS.

Now, the problem, Water after RO and DI is coming out at 8ppm at best no matter what the ratio. Partly this will be down to the fact that against my (and daqua's) advice, my wife is using a tiny 700ml DI canister to keep it "light". BUT, the RO by itself is not working correctly, pure end of the RO is reading 43ppm TDS, so only a 90% efficiency. I've also noticed that the gate valve/waste tap, even when fully closed still is on a 45waste/55pure ratio and does feel notchy, I assume this is knackered and adding to my problems? I also assume that the Membrane is done for, and that a booster would help, but not to the point where the TDS will drop into the teens just due to being at 80psi rather than 60psi in the RO?

OK, so I could just buy a nice big DI vessel and get the TDS down to 0, but id be eating the resin like nobodys business!
Is this a new membrane job and hope for the best? OR buy a new RO system and keep/sell the other for spares? Could it just be that its using an HF4 membrane rather than an HF5 and the booster WOULD solve it?
Any hints/tips/help is much appreciated, I'm new to all this and having to try and fix all the things that were done wrong to start with.....

Even if the answer seems obvious, I will need it all spelt out to me, Initiative never has been my strong point!

As I have said before, a second hand r/o is only worth the used value of the housings. When buying a used r/o you must account for having to replace the innards pretty soon after your r/o arrives. Hence the reason why I don't believe most used r/o's are worth what window cleaners believe they are worth.

What would I do? I would replace the membrane with an HF5 and forget the booster pump. (A booster pump will just add additional management issues you aren't experienced to deal with yet.) I don't believe a booster pump is necessary atm. It will be an added expense as I believe you will have to replace the membrane anyway.

I would also replace that di vessel for something bigger. Even with an efficient performing membrane your rejection rate is going to be around 12ppm. Its fine going 'lite', but it also needs to be practical.

My first r/o was included in a used system I bought. The system was a year old and the prefilters had never been changed. I had to replace those membranes shortly after I purchased it. The seller was on the same water supply as I was. After I replaced those membranes and did regular prefilter replacements, the new membranes lasted me 6 years.

If your waste gate valve is producing that ratio when closed then there is also the possibility that a small hole was drilled in the 'gate' Purefreedom do that and I thought it was a good idea and did it myself. I did it for 'safety' reasons. Now I know the gate valve can't be completely closed and damage the membrane.

What Doug is asking for is how much pure does your r/o produce in a minute. It should be close to 1 liter.

 

[Robt100]

@spruce Yeah its looking like new pre-filters and membranes are the "fix".
As for the valve, its a Daqua system, so hopefully Doug will know if it is normal or not. And it seems to be producing 2 litres of pure a minute, either that or the Jug at home is mucked up ? Makes me wonder if the membrane is knackered and letting more water through than it should hence the higher ppm and fast flow rate.

The reason for the booster pump idea is mainly down to efficiency, being on a water meter means It'd pay for itself quite soon I reckon. Only problem there being, total bank balance including life savings comes to a grand total of £240 at the moment, so replacement parts are a way off!

 

[spruce]

I see a bit of myself in you @Robt100. I struggled on with a 450GPD for a year when I knew that the 450GPD was too small to supply 3 of us with water. I procrastinated about upgrading the r/o. My son told me to replace the old membranes but I eventually made to right decision and upgraded to a 4040.

 

[spruce]

@spruce Yeah its looking like new pre-filters and membranes are the "fix".
As for the valve, its a Daqua system, so hopefully Doug will know if it is normal or not. And it seems to be producing 2 litres of pure a minute, either that or the Jug at home is mucked up ? Makes me wonder if the membrane is knackered and letting more water through than it should hence the higher ppm and fast flow rate.

The reason for the booster pump idea is mainly down to efficiency, being on a water meter means It'd pay for itself quite soon I reckon. Only problem there being, total bank balance including life savings comes to a grand total of £240 at the moment, so replacement parts are a way off!

I understand the predicament you are in financially. Unfortunately you can't earn without the right tools or equipment. I didn't realise how I stiffled the growth of our business by rationing water. Ask Doug what its like trying to run a car with strict petrol rationing. I was doing the same with too small an r/o.

My 4040 is twice the size of a 4021 and that produces 2 lpm of pure.

I am also going to add not to be drawn in by some cheap membrane offers around. You need the best membranes available and those don't come with a 'cheap' price tag.

 

[Robt100]

Sadly its a bit of a catch 22 situation at the moment. At least with my employment we can hopefully use the window cleaning income purely to get the business running. Hoping to get getting a grant for expansion/start-up which would solve the problem quite nicely!
Thankfully amount of water isn't a problem, its quality of water that is sadly the issue. But it'll get there, but from what you have all said it seems its a case of start again on the RO/DI front with new filters, membranes and vessels ?