[Fieldsy]

sorry, another resin useage thread.

Changed Resin on Wednesday (Tulsion from daqua). About 20 tds from 200gpd RO, and producing 000 tds after 2x700ml DI canisters. Have only produced 1200 litres since wednesday, gone out this morning and tds is now 024 !!!!!!.

Surely, this can't be correct ??. That means I'd be changing resin every couple of days. or every 1200 litres

So :

A) Is this useage correct   (which I doubt)

B) If its not, what the hell is causing the TDS to rise so bloody rapidly ??


Thanks for any input.


Fieldsy

[Nathanael Jones]

So by those figures you will get 21500 litres or so from a bag of resin?

That doesn't seem too bad to me,.. but you might get better results using 2 bigger DI vessels.

[Fieldsy]

Hi Nathanael,

Thanks for your input.................so you reckon this is about right. It just seemed so quick to be changing resin after 2-3 days (when everyone suggests it lasts for ages). Having read your estimation I worked on this.....am I correct??

I bought a 5 litre bag tulsion resin.

having 2 x 700ml di's means I should get 5litres/1.4 litres = usage from the bag, which equates to getting 3.57 lots of useage out of the resin.

1200 litres production per 1.4 litres resin, so 3.57 x 1200 litres= 4284 litres per 5 litre bag

Hence a 25 litre bag would equate to 21420 production of water.

Am I barking up the right tree Nathanael ?? and is this sort of production about right ??  If so, looks like I'll have to plod along until I get bigger vessels...lol


Thanks again

Fieldsy

[Ian Lancaster]

About 20 tds from 200gpd RO

What's your input tds?  I used to have a 300gpd RO-man and it would produce about 3-4ppm from input of 280-320

A 25lt bag of resin lasted me 18 months, then I realised anything less than about 8ppm was fine so didn't bother with resin anymore.

Now using a 40-40 and producing at 4ppm so still not bothering with resin

[Fieldsy]

Hi Ian,

Input tds is about 380-390

I checked the tds after the RO when I changed the resin and it was 20-21 with 000 after the di...............checked both again this morning tds after RO is still 20-21, but after DI is now 24, so I'm assuming its the DI or resin being used so quick.


Thanks Fieldsy

[David Kent @ KentKleen]

hi, hope this helps, I input the di vessel with water at around 17 to 20 ppm. I use half a bag of resin in my vessel and this lasts me 4 months @ 2500 ltrs a week. Double di and i think i could make 1 bag of resin last over 1 year. good luck

[Fieldsy]

I fill the two small 700ml Di's to the brim, would this make a difference ??

[Ian Lancaster]

Hi Ian,

Input tds is about 380-390

I checked the tds after the RO when I changed the resin and it was 20-21 with 000 after the di...............checked both again this morning tds after RO is still 20-21, but after DI is now 24, so I'm assuming its the DI or resin being used so quick.


Thanks Fieldsy

What RO are you using?  Even at 380-390 input your output seems very high to me.  What's your pressure at the membrane?  It should be at least 65psi and preferrably 75-90psi.  Do you have a booster pump?

I presume you flush regularly and have the correct pure/waste ratio?

[Window Washers]

Hi Ian,

Input tds is about 380-390

I checked the tds after the RO when I changed the resin and it was 20-21 with 000 after the di...............checked both again this morning tds after RO is still 20-21, but after DI is now 24, so I'm assuming its the DI or resin being used so quick.


Thanks Fieldsy

What RO are you using?  Even at 380-390 input your output seems very high to me.  What's your pressure at the membrane?  It should be at least 65psi and preferrably 75-90psi.  Do you have a booster pump?

I presume you flush regularly and have the correct pure/waste ratio?

Ian are you on a water meter ?

[Fieldsy]

Hi Ian,

I have an 85 psi booster pump. The membranes are approx a year old, so could do with changing...........but this doesn't alter the fact that its the same tds after the RO when the resultant tds after the DI is 000 or 024, but are you saying because the output is so high its wearing the resin out quicker , which would make sense.

Thanks for your input Ian


To be perfectly honest Ian, I have never changed the pure water/waste ratio as I wouldn't know how to go about doing it  or where for that matter

[Paul Coleman]

sorry, another resin useage thread.

Changed Resin on Wednesday (Tulsion from daqua). About 20 tds from 200gpd RO, and producing 000 tds after 2x700ml DI canisters. Have only produced 1200 litres since wednesday, gone out this morning and tds is now 024 !!!!!!.

Surely, this can't be correct ??. That means I'd be changing resin every couple of days. or every 1200 litres

So :

A) Is this useage correct   (which I doubt)

B) If its not, what the hell is causing the TDS to rise so bloody rapidly ??


Thanks for any input.


Fieldsy

Approximate calculations would be
500,000/TDS(20) = 25,000
So 25,000 litres of pure per 25kg bag of resin.
So that's about 1,000 litres per 1 kg of resin
OR
1,400 litres per 1,400 ml of resin.
OK so you got 1,200 litres rather than 1,400 but the numbers were approximations anyway so it sounds about right.
If you don't want to be changing resin so often maybe invest in a couple of larger vessels.
My TDS out of RO is about the same as yours.  It's not surprising because it's a merlin running under lowish pressure (c. 40 PSI).  That gave me a TDS out of 16.  However, due to being on a water meter, I have put a restrictor on the waste which pushes the TDS out of RO up to 21/22.  The cost of the extra resin will be far less than the higher water bill would have been.  Having the waste restrictor MAY reduce membrane life but the last lot managed 18 months.  I'll settle for that.

[Fieldsy]

Thanks Paul,

Using your formula works out approx correct. Its just that when you read others are getting a weeks, months even years out of resin, you start to wonder where you are going wrong, but I suppose everyones system is unique to themselves and usage of materials and water production will vary.

Compared to most, mine is a relatively small system 200gpd with 2x 700ml di's, so I'm probs asking a lot from it...lol.

I think its time for a couple of new membranes, bigger DI'S and not so much expectations.

Note: Just changed the resin again and its back to 000

Thanks for everyones input, appreciated.

Fieldsy

[john tomkins]

I use the exact same set up as you Fieldsy.
With water pressure of 55psi and tds in at 240, my output from membranes is 5tds.
If yours is 20tds then you will use resin 4x as quick as I do, so your resin use dont look too bad, it's your membranes that are the problem.
Try removing one membrane from your set up and try the tds out from that, then try the other just to check it's not the just one membrane giving you problems.

[daz1977]

the usuage is right, the problem you have got is the di vessels are 0.7 and people have 11 ltr ones,  buy a new di vessel and put in van and it will last longer and save u changeing all the time,

[john tomkins]

the usuage is right, the problem you have got is the di vessels are 0.7 and people have 11 ltr ones,  buy a new di vessel and put in van and it will last longer and save u changeing all the time,

The usage is about right for tds of 20 out of membrane, the problem is it shouldn't be anywhere near 20tds from a 200 gpd system, this is what needs addressing.

Having a bigger di vessel will only help by not having to change resin as often, he will still be using it up at a too high rate

[Window Washers]

the usuage is right, the problem you have got is the di vessels are 0.7 and people have 11 ltr ones,  buy a new di vessel and put in van and it will last longer and save u changeing all the time,

why put it in the van ? get a static system no need for any water making gear on board unless you have a mad day, then barrels can be used.

[Paul Coleman]

the usuage is right, the problem you have got is the di vessels are 0.7 and people have 11 ltr ones,  buy a new di vessel and put in van and it will last longer and save u changeing all the time,

why put it in the van ? get a static system no need for any water making gear on board unless you have a mad day, then barrels can be used.

Or better still have both.  I make my pure water from a static system but also have a reasonable sized DI vessel on board in case I need some extra to finish off (rarely happens).  When it does happen I can filter a bit of water DI only.  Obviously as I'm in a hard water area I avoid but sometimes it's cheaper to do that than return to job next day.  I would only do this for small amounts of course.

[AuRavelling79]

Change your membranes - less than £30 each from soap national all in. Change them once a year or when they get to about 20tds. From new once they've bedded in you should get about 8ppm.

[Fieldsy]

Just to say, thanks for everyones input and suggestions. Firstly as suggested, I'll go down the route of new membranes, found them at purefreedom for £19.99+vat.............and secondly look into getting a larger DI. Is it simply a case of buying an 11 litre one and plugging it in place of the 2x 700ml ??.

Thanks once again, I'm sure all this will increase my useage and the info has been greatly received.

Fieldsy

[Jays Window Cleaning]

Sounds excatly like the way i go through resin i have a 300 gpd ro and change my resin every 4 - 5 days but i do produce a lot of water. Really i need a bigg ro and a bgger di . I have been looking at the new Ro system that pure freedom are doing now ok its expensive but if im going through resin like i am in the long run its goona work out the same. any one tried on yet?

jay