RO filter TDS readings


Joined
9 Sep 2014
Posts
238
Reaction score
8
Location
Vaal Triangle
Recently i bought a new membrane for my RO/DI filter, as well as a TDS meter. I disconnected the Resin chamber, inserted the new membrane and flushed it for around an hour or so. I then tested the water which was coming out and it gave me a 0ppm reading. I then connected the Resin chamber and started filling a drum, which i filled halfway. When i tested the water in the drum , it gave me a 14ppm reading... What would be the cause of this, is it perhaps something to do with the resin, or maybe the drum i used was not rinsed and still had some salt/dirt inside?
 
Joined
8 Jul 2011
Posts
241
Reaction score
135
Location
Cape Town, Lakeside
I agree, 14 is pretty high even for RO water, I rate its the drum, that needs a good clean with RO Water As normal tap water will leave behind unwanted elements. Good luck
 
Last edited:

Quintus

the irish aXeman
Joined
11 Jan 2010
Posts
546
Reaction score
44
Location
Houtkop AH, Vereeniging
are you talking about 14 ppm in tapwater? never, unless this 14 is a filtered reading from tap

even in the States the average is between 60 to 140ppm TDS depending where
the tap water from my house is 112ppm
my borehole give me 84 average , these readings are before RO
 
Last edited:
Joined
30 Nov 2014
Posts
772
Reaction score
133
Location
Alberton
if it isn't the drum it clears out after a bit, if I bump my RO unit i get a few minutes of 2-3ppm water instead of 0ppm, after I swopped all my filters out 6 months ago it took about 1000l of about 9ppm to 3 ppm, eventually it cleared again. I also asked the manufacturer, unfortunately they didn't have an answer for me. I was also concerned.
 
Joined
9 Sep 2014
Posts
238
Reaction score
8
Location
Vaal Triangle
How much RO water is being made at a time?
the most I make at a time is 100 liters. I made around 50 or less last night when it gave the 14ppm reading. Other than that the only times I make 5 or 10 liters. I also flush for about 2 minutes weekly
 
Joined
7 Feb 2009
Posts
8,370
Reaction score
286
Location
Joe's Mountain
Yes membranes that are used to make small batches of water and that are infrequently used can shorten the lifespan of the membrane.

What resin do you have in the resin chamber?

Did you replace the carbon block and sediment filters?
 
Joined
9 Sep 2014
Posts
238
Reaction score
8
Location
Vaal Triangle
Yes membranes that are used to make small batches of water and that are infrequently used can shorten the lifespan of the membrane.

What resin do you have in the resin chamber?

Did you replace the carbon block and sediment filters?
I replaced the 2 pre filters a few months back. Using the resin from Waterboy
 
Joined
9 Sep 2014
Posts
238
Reaction score
8
Location
Vaal Triangle
And the resin? When did you replace that? Has it gone brown?
I replaced yesterday. I used a little that i had left over (pack was re-sealed properly) and filled the rest with some new resin i bought. It did look though like the older resin was a little drier than the new resin, but not much really. It is all still a bluish colour
 
Last edited:
Joined
7 Feb 2009
Posts
8,370
Reaction score
286
Location
Joe's Mountain
Sounds all good. Next time you make water, flush the system, then run through about 10L, Discard that 10L, then test the TDS of new water.

You did check the calibration of you TDS meter?
 
Last edited:
Joined
9 Sep 2014
Posts
238
Reaction score
8
Location
Vaal Triangle
Sounds all good. Next time you make water, flush the system, then run through about 10L, Discard that 10L, then test the TDS of new water.

You did check the calibration of you TDS meter?
Nope, how do you check calibration? Tap water gave mee 114ppm reading, waste water gave me 166ppm . I got a 0ppm reading before i hooked up resin chamber. I will still take a small sampleof new water later and test.
 
Joined
7 Feb 2009
Posts
8,370
Reaction score
286
Location
Joe's Mountain
Nope, how do you check calibration? Tap water gave mee 114ppm reading, waste water gave me 166ppm . I got a 0ppm reading before i hooked up resin chamber. I will still take a small sampleof new water later and test.
Give Marco a call. He has the calibration fluid.
 
Joined
9 Sep 2014
Posts
238
Reaction score
8
Location
Vaal Triangle
Looks like it's just a dirty drum. I made water in other containers all with zero ppm readings . Will rinse the drum nicely over the weekend
 
Top Bottom