[Stevie Behan]

Hi Guys,

Ive just set up my RO & DI system and am wondering how long I have to run it for before I get a reading of 0 on my TDS?

At present I am filling up a water butt to try and flush the system through (currently getting a reading of 14).

Any advice on how long this is likely to take would be appreciated. Alternatively if the reading doesnt go to 0, is there a chance my system is connected up wrongly?

Thanks
Steve

[matty72]

no expert mate, but your ro should get your water down to hopefully below 10 maybe 20 or even 30 depending on water and ro system but the di then takesit down to 0

[Neil Williams]

If you've got DI on the system then it will produce 0 straight away, but, it is advisable to run the filters and membranes for a few hundred litres before actual production in order to get any preservatives etc out of the filters/membranes, plus, the lower the reading going into the DI the longer the resin will last.
I'm not aware of any RO (without DI) that produces 0
Some systems will get it down to 4 or 5 on a good day although the fast production systems rarely get below 15 - 20.

[Stevie Behan]

Cheers for the replys.

I have just been out to check the reading again and it has gone down to 9. Its got DI on the system, so just a bit confused as to why it hasn't gone down to 0 straight away.

Is there a chance the filter may need putting in again? Ive tried to look through the troubleshoot guide in the instruction manual, but its crap:(

On a side note, I have managed to flood my garage as i'd left the tap open on the water butt!! Water every where - havent told the wife yet

[Neil Williams]

I have just been out to check the reading again and it has gone down to 9. Its got DI on the system, so just a bit confused as to why it hasn't gone down to 0 straight away.

If it's reading 9 after DI then you have a problem.
Are you able to get a reading after it has been through the RO BEFORE it goes into DI
This is the real key as to what is going on

[Richard 01903]

As above check water after ro but before Di ,It should be some where around 20 /10 before then put through Di to finish off :

[Stevie Behan]

How do I go about doing this? I guess I just remove the DI filter then just run the system as normal?

[Neil Williams]

How do I go about doing this? I guess I just remove the DI filter then just run the system as normal?

Yes and get your reading from the water produced at that point

[Richard 01903]

I allways run mine through ro first into tank ,then from tank through DI into van tank.
From Ro 10, then from DI to van 0 

[Stevie Behan]

I just did another test and its now down to 5 on the TDS. So although its going down its still not at 0

I then removed the DI and the reading of the water coming through the system was at 14.

I assume this reading is OK? Could my problem be with the DI cartridge I was sent?

Any suggestions? For the time i'm gonna keep running in the hope that it will keep lowering over time, but I am conscious of wasting the DI.

[Richard 01903]

check your resin level !! If your water is coming out RO at 14 then resin will take it to 0 :

[Stevie Behan]

Cheers Richard.

Its a brand new system I bought the other day and the resin was also purchased at the same time to go with it. Ive checked it anyway and it appears to still have plenty of resin left.

Maybe a call on Monday to the supplier. He's been pretty helpful so far, so hopefully he can point me in the right direction.

Was also just thinking, maybe my TDS meter could be faulty!!

[Spruce]

Hi Steve,

If you have the older conventional R/O (3 container housing below for sediment, carbon and resin with the membrane housings above), then according to Ro-Man your membrane should remove between 97-99% of contaminants with the correct water pressure.
I was once told by Ro-Man that the USA manufactured membranes, although more expensive that the Chinese copies, are more efficient and over time are more cost effective as you will use less resin.

A fellow window cleaner in town has just replaced his Merlin with another, and although he produces water much faster than I do, his system only works at about 90% effeciency.

Spruce

[Stevie Behan]

The TDS reading from the mains supply is coming out at 338 and once through the system (without DI) is going to 14.

Looking through the instructions/suppliers guide it says to make sure all connections are tight enough, so think thats next port of call.

The system I have is a basic 100gpd with pump from John Hewitts
http://www.johnhewitt.com/ro.htm

[Richard 01903]

If your getting it to 14 from RO then it should come out of DI at 0, if it doesnt then it the DI that needs sorting

[Spruce]

The TDS reading from the mains supply is coming out at 338 and once through the system (without DI) is going to 14.

Looking through the instructions/suppliers guide it says to make sure all connections are tight enough, so think thats next port of call.

The system I have is a basic 100gpd with pump from John Hewitts
http://www.johnhewitt.com/ro.htm

So your R/O is running at 96% effeciency. And yes the resin in the R/O should polish it off the zero. If you have a 3rd container as a resin filter, your resin won't last that long as it doesn't contain very much.
With the water as hard as yours is it may be well to invest in a larger separate DI if you haven't got one.

Spruce