Ratio issues..................

[Norf86]

Okay, so I have a 4021 ro with double di setup in the garage. I'm producing lots of lovely pure but I've never achieved a ratio of 60/40. It seems I can only get about 80/20 or 70/30 at best. 

I have a tap pressure of 40psi and a 95% rejection rate. I have a hf5 membrane which works best with a 80psi tap pressure, so I expect a below average rejection rate. I'm currently producing approximately 800ml of pure per minute or 48 litres per hour. 

Does this sound about right for my current setup? I can't help thinking that my ratio should be better. Will my ratio improve along with the rejection rate with a booster pump? Scares me how much water is going down the drain!! 

Tia

 

[spruce]

Okay, so I have a 4021 ro with double di setup in the garage. I'm producing lots of lovely pure but I've never achieved a ratio of 60/40. It seems I can only get about 80/20 or 70/30 at best. 

I have a tap pressure of 40psi and a 95% rejection rate. I have a hf5 membrane which works best with a 80psi tap pressure, so I expect a below average rejection rate. I'm currently producing approximately 800ml of pure per minute or 48 litres per hour. 

Does this sound about right for my current setup? I can't help thinking that my ratio should be better. Will my ratio improve along with the rejection rate with a booster pump? Scares me how much water is going down the drain!! 

Tia

Most of us with these types of r/o (4021 & 4040) have a gate valve on the waste outlet of the r/o where we can adjust the rate of water going to waste. I close mine until I achieve the restriction I want. For me its around 55% waste to 45% pure. I've marked the handle so when I flush the r/o I can go back to the setting quickly.

This ratio gives me purest pure before di. I have an inline TDS meter so if needed I can tweak the waste gate valve until I achieve the r/o's sweet spot.

If you look at my r/o set up, the gate valve has a red wheel handle. ATM our water pressure is 45psi and my pure before di is 3ppm from 132ppm tap water. Membrane is an HF5 and 8 years old.

 

[Norf86]

Most of us with these types of r/o (4021 & 4040) have a gate valve on the waste outlet of the r/o where we can adjust the rate of water going to waste. I close mine until I achieve the restriction I want. For me its around 55% waste to 45% pure. I've marked the handle so when I flush the r/o I can go back to the setting quickly.

This ratio gives me purest pure before di. I have an inline TDS meter so if needed I can tweak the waste gate valve until I achieve the r/o's sweet spot.

Yes I have a red gate valve and I've kinda got a sweet spot but when I compare my waste hose output to my pure hose output it never looks like 60/40 or 55/45 more like 80/20. Even when the gate is almost fully closed. Like I said I'm creating a good amount of pure ( I think) but I dread how much waste I'm creating as well. Starting to think I may have a faulty gate valve or something, if at all possible?! 

 

[spruce]

Yes I have a red gate valve and I've kinda got a sweet spot but when I compare my waste hose output to my pure hose output it never looks like 60/40 or 55/45 more like 80/20. Even when the gate is almost fully closed. Like I said I'm creating a good amount of pure ( I think) but I dread how much waste I'm creating as well. Starting to think I may have a faulty gate valve or something, if at all possible?! 

While the r/o is running pure the pure into a 25 litre container and fill it for a minute. Pour the pure out into a kitchen measuring jug. At the most you will have to fill a 1 litre jug twice. Then do the same for your waste to the drain. Compare both results to get a ratio.

Or:

You could put two 25 litre plastic containers together and fill them at the same time. Your waste should be slightly more than your pure over any given time.

 

[Norf86]

Most of us with these types of r/o (4021 & 4040) have a gate valve on the waste outlet of the r/o where we can adjust the rate of water going to waste. I close mine until I achieve the restriction I want. For me its around 55% waste to 45% pure. I've marked the handle so when I flush the r/o I can go back to the setting quickly.

This ratio gives me purest pure before di. I have an inline TDS meter so if needed I can tweak the waste gate valve until I achieve the r/o's sweet spot.

If you look at my r/o set up, the gate valve has a red wheel handle. ATM our water pressure is 45psi and my pure before di is 3ppm from 132ppm tap water. Membrane is an HF5 and 8 years old.

View attachment 25373

That's a tidy setup BTW.. 

 

[Norf86]

While the r/o is running pure the pure into a 25 litre container and fill it for a minute. Pour the pure out into a kitchen measuring jug. At the most you will have to fill a 1 litre jug twice. Then do the same for your waste to the drain. Compare both results to get a ratio.

Or:

You could put two 25 litre plastic containers together and fill them at the same time. Your waste should be slightly more than your pure over any given time.

Thanks I will try this. I've read on here that the best way is to compare both the waste and pure hoses side by side. I'm starting to think that my visual judgement is a bit off. Hopefully it's just that! 

 

[doug atkinson]

It sounds like that your Gate Valve has pew drilled hole in it.

 

[Norf86]

It sounds like that your Gate Valve has pew drilled hole in it

I Was going to call you earlier but thought I'd check my bible first! 

Is this a common fault then or something? Never heard of it 

 

[doug atkinson]

I Was going to call you earlier but thought I'd check my bible first! 

Is this a common fault then or something? Never heard of it 

Where did you get the system from!

 

[Norf86]

Where did you get the system from!

I bought it from you! 4021 system, not the portable one. 

 

[doug atkinson]

I bought it from you! 4021 system, not the portable one. 

I take it you’ve just purchased a new one as cannot judge from your forum. Or did you purchase it second hand.

As you start to close the Gate Valve the waste water starts to reduce and pure increases. But never have less waste than pure.

 

[Norf86]

I take it you’ve just purchased a new one as cannot judge from your forum. Or did you purchase it second hand.

As you start to close the Gate Valve the waste water starts to reduce and pure increases. But never have less waste than pure.

It was new from you, back in November I think. Yes the pure increases and the waste definitely reduces as I close the gate valve but can't seem to get near to a decent ratio. I will do some more tests as I might be misjudging it. I will give you a bell if I can't figure it out. 

Cheers 

 

[doug atkinson]

Make sure you do the measurements with it not connected to the DI Vessel. Feel free to call us tomorrow 

 

[Norf86]

Make sure you do the measurements with it not connected to the DI Vessel. Feel free to call us tomorrow 

Hi tests complete and yep I was misjudging it! I'm producing approx 850 ml of pure to just over a litre of waste.

My rejection rate is still not great at about 95% so I'm going to get a booster pump at some point. Thanks all for advice ?