[simon w]

I have been using my pure water cleaning system for one month and have not been able to acheive a TDS reading as low as i would have expected.

My tap water here is 315 PPM. The system i have is a 1000Lt garage filteration system, which consists of a 4"x40" RO, and a 20" particulate filter & a 20"carbon filter.

My treated water is then transfered into a 650Lt van system which is set up for a two man operation. this has two 11Lt Di vessels which are filled with Purelite Di resin.

The problem i have is since receiving my system the water after going through the 3 stage garage system is ranging between 25PPM - 40PPM. do you think this is acceptable? How can i get TDS reading lower?.

After taking a TDS reading today the water quality after going through the Di vessels has crept up to 2PPM. Should the Di resin have been depleted after only one months use.

Can anyone offer any advice on the quality of my treated water.
or does the readings that i have quoted sound acceptable.
My tap water pressure here is 65PSI.

Thanks Simon..

[P®oPole™]

No it should be lower mate. Have you been flushing off your ro? should be done at least once a week, also is your waste water set right?

[simon w]

Propole.

I flush the RO at least twice a week for about 15min per flush. The waste water is set ok, the ratio of waste water is set greater than the pure water feeding into the 1000Lt tank.

Do you think that the two pre filters may have been sub-standard when i received the system? would this explain a slightly higher TDS reading than expected?.

Untill today the TDS reading after coming out the Di vessels has been 0PPM.
but after taking a reading today it was 1PPM. I have tried shaking the Di vessel as i have been told this can improve the TDS reading for a while before having to change your resin.

I know you dont need to think about changing your Di resin untill it reaches 8-9 PPM, but i was expecting to have a reading of 0PPM for quite a bit longer than one month. as i would like to keep the cost of making pure water as low as possible.

Apart from a few technical problems over the past month WFPing has been a good decision for my business. & is providing good results. and making the physical aspects of the job a lot easier.

[JM123]

Was the 4040RO new when you purchased it??  If it was then it sounds to me like its a dodgy membrane.

[simon w]

 Yes the complete system is brand new only one month old.

The supplier has told me that the readings i have got should not be a concern!
but i was expecting to have a TDS reading a lot lower than 25-40 PPM.
And i was hopeing that the resin would give me a reading of 0PPM for longer than just one month.

[chris@c.m.s]

Simon not sure if it makes any differance in you case but with my ro it takes a good few minutes for the tds to drop from the ro unit after turning the tap on, so for a short time your Ro could be filling your tank with quite a high tds your then putting that through your di vessels and depleting it quickly, perhaps you could check your tds from the ro after its been off for an average length of time then again after the Ro has been running for a while, not that I know much about wfp systems so its just my experiance of things and info taken from the forum hope it helps.       

[simon w]

Thanks Chris: I took into consideration the time it takes for the TDS reading to come down after a back-fill. The 25-40PPM is a reading taken after the waste tap has been correctly adjusted and time allowed for pure water to fill the tank.

Simon..

[macc]

Simon. Have you taken a tds reading of pure water in your holding tank?

Macc

[Paul Coleman]

I have been using my pure water cleaning system for one month and have not been able to acheive a TDS reading as low as i would have expected.

My tap water here is 315 PPM. The system i have is a 1000Lt garage filteration system, which consists of a 4"x40" RO, and a 20" particulate filter & a 20"carbon filter.

My treated water is then transfered into a 650Lt van system which is set up for a two man operation. this has two 11Lt Di vessels which are filled with Purelite Di resin.

The problem i have is since receiving my system the water after going through the 3 stage garage system is ranging between 25PPM - 40PPM. do you think this is acceptable? How can i get TDS reading lower?.

After taking a TDS reading today the water quality after going through the Di vessels has crept up to 2PPM. Should the Di resin have been depleted after only one months use.

Can anyone offer any advice on the quality of my treated water.
or does the readings that i have quoted sound acceptable.
My tap water pressure here is 65PSI.

Thanks Simon..

TDS after RO does sound a bit on the high side.  Mine is still 006 - 007 (though tap water TDS is lower at 200) after 6 months and mine is a system that can't be back flushed.  From what I've read on here, I understand that low water pressure can cause higher TDS on some systems but I would have thought that your 65PSI was enough.
Resin durability is calculated at 500,000/TDS for a 25 kilo bag.  At an average TDS of 035, that should mean about 14,000 litres per 25 kilos.  So I suppose an 11 litre vessel would give around 6,000 litres.  If the resin in the first vessel in line is spent, I've heard that it can contaminate the water thereby passing an even higher TDS to the second vessel.  If so, this would use up the resin in the second vessel more quickly.  Are you able to test the water between the two vessels?  Some people discard the resin in the first vessel, then switch vessel 2 to the vessel 1 position.

[Ian_Giles]

Your tap water pressure isn't too bad, but it isn't that good either.

Low pressure will certainly affect the performance of your R/O. perhaps a booster pump would improve it's performance?

There is no way that you should be left with such a high TDS reading after it has passed through your R/O.
And yes, with a TDS that high (25-45) you will eat through resin at a fair old rate.

Although your tap water TDS is pretty high isn't it?
The tap water around my location is around 0.168 ppm and my small R/O system brings that down to 0.001-0.005 ppm.

I think that somone with the same size R/O as you needs to reply to this one, they also need to have a high tap water reading too.

I do know that Roy Harding has the same size R/O as yourself, and I also know he sets his pure/waste ratio @ 1:1
His R/O is a couple of years old (roughly) and at last count was reducing his tap water down to approx 0.001 ppm.
But he does have a lower tap water TDS reading than you do.

If possible you need to have a mains pressure above 80 psi to obtain top results with an R/O.

Ian

[Roy Harding]

Hi Simon

I have the same setup.

My tap tds is 234 and as Ian said is still coming out at 0.01 after pre fillters and r/o.

My tap water is 80 psi.

The Carbon fillters can be carbon granuals or carbon block, the better of the to is carbon block. I  do know of someone who had the granuals and the fillter split and all the granuals flushhed into the r/o.

The other pre fillter is a 5 micon seddiment fillter.

I have a 25ltr resin colum and that will last 12 months.

I would take out carbon fillter and check its not broken down and if you shake it you  can hear if it is granuals.

If it has not broken down I would change them and resin, I change my pre fillters every 6 months and set a reminder on my phone to alert me.

Your water preasure is I feel the promblem, you need to be up around 80psi and over. A booster pump would slove that.

Roy

[steve m]

hi simon

  I have a slightly higher ppm reading at the tap being 324 .when i rung ro-man they supplied a 4 stage ro sytem and a di polisher after this, and so far I have had to change the resin once, but mine is a lot smaller than yours being a 10" housing with a refillable cartridge inside

[JM123]

wow - I've only got 45psi out of the tap - I still get 1800 - 2000ltrs a day from my merlin at 5-8ppm - can't understand why your 4040 isn't doing at least that!