tds readings

[robin.gordon1]

I've just purchased a 6 stage 100 GPD (nowhere near that) RO unit and have
ran it for a full day now most of that time was flushing the membranes and
the TDS readings were thus.
tap water = 210ppm
during flush = 10ppm.
after flush and tap switched to produce RO water = 11ppm.
now I have disguarded the first 40 litres of water and am now collecting the
RO in a water butt. the reading is still 11ppm but now I keep getting
static shocks when I get near the water.
anyone with similar experiences and what readings should I be getting before
I start using this water for water-changes.

Robin

[CapFusion]

"robin.gordon1" > wrote in message
...
> I've just purchased a 6 stage 100 GPD (nowhere near that) RO unit and have
> ran it for a full day now most of that time was flushing the membranes and
> the TDS readings were thus.
> tap water = 210ppm
> during flush = 10ppm.
> after flush and tap switched to produce RO water = 11ppm.
> now I have disguarded the first 40 litres of water and am now collecting
the
> RO in a water butt. the reading is still 11ppm but now I keep getting
> static shocks when I get near the water.
> anyone with similar experiences and what readings should I be getting
before
> I start using this water for water-changes.
>


Humm.... getting 10-11ppm product water on RO.... depend on the carbon /
sediment / PSI. What are those size of those? Water pressure have major
affect of the product water. With 100GPD, higher pressure about 80PSI range.
Low pressure will have lesser effecient which will pass more nutrient
[higher ppm].

I have 5 stage RO with the following -
1 sediemnt = 1 micron
2 carbon = 1 micron
1 membrane = 75GPD
1 post carbon = ?? do not remember at ths time.
45 PSI
Getting 4ppm product water.

From tap = 245ppm

CapFusion,...

[robin.gordon1]

the stages are thus;

100 gallon per day membrane
5 micron sediment pre-filter
1 solid carbon block filter
1 GAC coconut carbon filter
1 inline carbon filter
1 inline DI filter
pressure= ?

tap = 211ppm
RO = 011ppm

i thought that i could put up with a slow production but not poor water
quality, especially with the money spent. surely 11ppm is a lot better for
my reef than 210ppm. i did have a tapwater purifier but i'm not sure of
it's quality. i'd be a bit peeved if it's better.

Robin

[Pszemol]

"robin.gordon1" > wrote in message ...
> the stages are thus;
>
> 100 gallon per day membrane
> 5 micron sediment pre-filter
> 1 solid carbon block filter
> 1 GAC coconut carbon filter
> 1 inline carbon filter
> 1 inline DI filter
> pressure= ?
>
> tap = 211ppm
> RO = 011ppm

I have KENT 10gpd barebone system: prefilter with carbon and sediment
filter, after TFC membrane I have KENT DI stage with mixed bed resin.
After membrane I read 5-6ppm, after DI stage, when water is dripping
from the pipe it is 0-1ppm. When the water collects in the bucket and
equilibrate with the air (mostly CO2) it could have high tds readings.
CO2 dissolved in water could decrease water resistance measured with
TDS meter increasing readings.

> i thought that i could put up with a slow production but not poor water
> quality, especially with the money spent. surely 11ppm is a lot better for
> my reef than 210ppm. i did have a tapwater purifier but i'm not sure of
> it's quality. i'd be a bit peeved if it's better.

Check directly water dripping from the product line.
In your case, it will not drip but flow rapidly, I guess ;-)

[erik]

3 stages of carbon filtration sounds funny to me.
My Culligan RO unit has a 5 micron sediment/carbon stage followed by
an RO membrane.
Since it's a CTA membrane I'm only getting about a 95% rejection of
"bad stuff"

11 ppm / 210 ppm = 95% rejection

Sounds ok for RO to me but with the DI stage you should be doing
better.

I'd take a look at the output of the various stages to see what each
is doing.

DI alone should get that water very, very clean if it's new.


Erik



On Thu, 05 Aug 2004 18:09:06 GMT, "robin.gordon1"
> wrote:

>the stages are thus;
>
>100 gallon per day membrane
>5 micron sediment pre-filter
>1 solid carbon block filter
>1 GAC coconut carbon filter
>1 inline carbon filter
>1 inline DI filter
>pressure= ?
>
>tap = 211ppm
>RO = 011ppm
>
>i thought that i could put up with a slow production but not poor water
>quality, especially with the money spent. surely 11ppm is a lot better for
>my reef than 210ppm. i did have a tapwater purifier but i'm not sure of
>it's quality. i'd be a bit peeved if it's better.
>
>Robin
>

[Pszemol]

"erik" > wrote in message ...
> 3 stages of carbon filtration sounds funny to me.
> My Culligan RO unit has a 5 micron sediment/carbon stage followed by
> an RO membrane.
> Since it's a CTA membrane I'm only getting about a 95% rejection of
> "bad stuff"

Hm... you have carbon filter in front of your CTA membrane... strange.
I understand CTA membrane is made from organics (cellulose) and
needs chlorine in the water to kill bacteria chewing on cellulose...
Your carbon filter is removing chlorine from the incoming water...
How long do you use your setup? Is it DIY or purchased complete?

[erik]

It's semi-DIY.
My father owns a Culligan dealership ( Culligan is a national
residential and commercial water treatment company in the US ) and put
it together from parts he had laying around.
It was a TFC membrane for several years. Then when I asked him for a
replacement he grabbed me a CTA.
A few months after I got it I came across an article stating that
there were potential problems with non chlorinated water and CTA
membranes. I asked my father about it ('cause he's supposed to know
these things) and he said that there should be nothing to worry about.
Well water is full of bacteria and therefore would destroy the CTA
membrane. But city water is chlorinated and should be bacteria free.
The carbon prefilter removes the chlorine so the water reaching the
CTA membrane should be chlorine and bacteria free.

Any thoughts? Is my logic incorrect?


Erik


On Fri, 6 Aug 2004 08:38:17 -0500, "Pszemol" >
wrote:

>"erik" > wrote in message ...
>> 3 stages of carbon filtration sounds funny to me.
>> My Culligan RO unit has a 5 micron sediment/carbon stage followed by
>> an RO membrane.
>> Since it's a CTA membrane I'm only getting about a 95% rejection of
>> "bad stuff"
>
>Hm... you have carbon filter in front of your CTA membrane... strange.
>I understand CTA membrane is made from organics (cellulose) and
>needs chlorine in the water to kill bacteria chewing on cellulose...
>Your carbon filter is removing chlorine from the incoming water...
>How long do you use your setup? Is it DIY or purchased complete?

[Pszemol]

"erik" > wrote in message ...
> But city water is chlorinated and should be bacteria free.
> The carbon prefilter removes the chlorine so the water reaching the
> CTA membrane should be chlorine and bacteria free.
>
> Any thoughts? Is my logic incorrect?

Logic would be correct if you did not underestimate bacteria.
Exchange "city water is bacteria free" with "city water has
less bacteria than well water". City water is NOT sterile and with
no chlorine presence bacteria will quickly populate your membrane.
Remember, bacteria multiply much, much faster than rabbits... ;-)
But hey - your father is the expert in this subject so do not listen to me.
If bacteria chew up on your membrane he will grab another for you ;-)
Just check your tds readings every month :-))

[CapFusion]

"robin.gordon1" > wrote in message
...
> the stages are thus;
>
> 100 gallon per day membrane
> 5 micron sediment pre-filter
> 1 solid carbon block filter
> 1 GAC coconut carbon filter
> 1 inline carbon filter
> 1 inline DI filter
> pressure= ?
>
> tap = 211ppm
> RO = 011ppm
>
> i thought that i could put up with a slow production but not poor water
> quality, especially with the money spent. surely 11ppm is a lot better
for
> my reef than 210ppm. i did have a tapwater purifier but i'm not sure of
> it's quality. i'd be a bit peeved if it's better.
>
> Robin
>
>
I did not notice you have a DI stage from your previous message. You should
be getting close to non-detetable or close to zero from DI output. What
micron size on your 2 carbon block?

CapFusion,...

[erik]

Your argument makes sense. My source of info has not always been as
right as he would like me to believe.

Has anyone else had experience with this? I did a lot of research at
the time and didn't find much on the web discussing non-chlorinated
water and CTA membranes.

Anyway, my TDS readings still look ok. Not great but I though they
were OK for CTA.
My new TDS meter is on loan to a friend but the readings I got a
couple of weeks ago were roughly :
tap = 850
RO = 80

Erik




On Fri, 6 Aug 2004 09:16:56 -0500, "Pszemol" >
wrote:

>"erik" > wrote in message ...
>> But city water is chlorinated and should be bacteria free.
>> The carbon prefilter removes the chlorine so the water reaching the
>> CTA membrane should be chlorine and bacteria free.
>>
>> Any thoughts? Is my logic incorrect?
>
>Logic would be correct if you did not underestimate bacteria.
>Exchange "city water is bacteria free" with "city water has
>less bacteria than well water". City water is NOT sterile and with
>no chlorine presence bacteria will quickly populate your membrane.
>Remember, bacteria multiply much, much faster than rabbits... ;-)
>But hey - your father is the expert in this subject so do not listen to me.
>If bacteria chew up on your membrane he will grab another for you ;-)
>Just check your tds readings every month :-))

[CapFusion]

"erik" > wrote in message
...
> Your argument makes sense. My source of info has not always been as
> right as he would like me to believe.
>
> Has anyone else had experience with this? I did a lot of research at
> the time and didn't find much on the web discussing non-chlorinated
> water and CTA membranes.
>
> Anyway, my TDS readings still look ok. Not great but I though they
> were OK for CTA.
> My new TDS meter is on loan to a friend but the readings I got a
> couple of weeks ago were roughly :
> tap = 850
> RO = 80
>

Humm....
From tap = 850? I have not seen this high reading before or know anyone
else. Do you know anyone have TDS meter or can you double check this reading
with your LFS [if possible]? Could this be a bad TDS meter? It just a guess
here.

CapFusion,....

[erik]

Sorry, my mistake. Too many percosets that night :o)
That would be 850 uS and 80 uS respectively.
I know that's still pretty high so maybe the meter does need
calibration. It's a Hanna Instruments 98311 EC/TDS & Temperature
Meter. It's new, right out of the box and probably does need
calibration. But regardless of the actual values, 80 is roughly 10%
of 850 which was the point I was trying to make.

Sorry for the confusion,
Erik

On Mon, 9 Aug 2004 13:16:49 -0700, "CapFusion"
<CapeFussion...@hotmail.., com> wrote:

>
>"erik" > wrote in message
...[i]
>> Your argument makes sense. My source of info has not always been as
>> right as he would like me to believe.
>>
>> Has anyone else had experience with this? I did a lot of research at
>> the time and didn't find much on the web discussing non-chlorinated
>> water and CTA membranes.
>>
>> Anyway, my TDS readings still look ok. Not great but I though they
>> were OK for CTA.
>> My new TDS meter is on loan to a friend but the readings I got a
>> couple of weeks ago were roughly :
>> tap = 850
>> RO = 80
>>
>
>Humm....
>From tap = 850? I have not seen this high reading before or know anyone
>else. Do you know anyone have TDS meter or can you double check this reading
>with your LFS ? Could this be a bad TDS meter? It just a guess
>here.
>
>CapFusion,....
>

[Boomer]

"That would be 850 uS and 80 uS respectively."

And roughly divide by 2 for TDS

850 = 425 TDS

80 = 40 TDS

You have some hard water but I have seen higher. EPA drinking std are not to exceed 500
TDS (IIRC)
--
Boomer

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If You See Me Running You Better Catch-Up
"erik" > wrote in message
...
: Sorry, my mistake. Too many percosets that night :o)
: That would be 850 uS and 80 uS respectively.
: I know that's still pretty high so maybe the meter does need
: calibration. It's a Hanna Instruments 98311 EC/TDS & Temperature
: Meter. It's new, right out of the box and probably does need
: calibration. But regardless of the actual values, 80 is roughly 10%
: of 850 which was the point I was trying to make.
:
: Sorry for the confusion,
: Erik
:
: On Mon, 9 Aug 2004 13:16:49 -0700, "CapFusion"
: <CapeFussion...@hotmail.., com> wrote:
:
: >
: >"erik" > wrote in message
: ...
: >> Your argument makes sense. My source of info has not always been as
: >> right as he would like me to believe.
: >>
: >> Has anyone else had experience with this? I did a lot of research at
: >> the time and didn't find much on the web discussing non-chlorinated
: >> water and CTA membranes.
: >>
: >> Anyway, my TDS readings still look ok. Not great but I though they
: >> were OK for CTA.
: >> My new TDS meter is on loan to a friend but the readings I got a
: >> couple of weeks ago were roughly :
: >> tap = 850
: >> RO = 80
: >>
: >
: >Humm....
: >From tap = 850? I have not seen this high reading before or know anyone
: >else. Do you know anyone have TDS meter or can you double check this reading
: >with your LFS [if possible]? Could this be a bad TDS meter? It just a guess
: >here.
: >
: >CapFusion,....
: >
:

[CapFusion]

"Boomer" > wrote in message
...
> "That would be 850 uS and 80 uS respectively."
>
> And roughly divide by 2 for TDS
>
> 850 = 425 TDS
>
> 80 = 40 TDS
>
> You have some hard water but I have seen higher. EPA drinking std are not
to exceed 500
> TDS (IIRC)

Thank Boomer.

Erik,
Ahh... that more about right. But as for the product from RO should not be
that high with 100GPD. IIRC from previous post, you have DI unit too. From
that DI output should be close to non-detectable. From your RO output, that
seem to be still high. 40TDS is similar to SF water without using any RO
unit.

You might want to check what the PSI before going into the unit. Do your RO
have a PSI meter? If so, what it indicating?

CapFusion,...

[erik]

No DI yet. I'm looking into building one. PVC pipe is cheap :o)

Anyway, 40 ppm TDS may still be high but if I'm getting a 90 to 95 %
reduction in TDS after the RO should I be expecting better of a CTA
membrane?


Erik

On Fri, 13 Aug 2004 13:12:11 -0700, "CapFusion"
<CapeFussion...@hotmail.., com> wrote:

>
>"Boomer" > wrote in message
...
>> "That would be 850 uS and 80 uS respectively."
>>
>> And roughly divide by 2 for TDS
>>
>> 850 = 425 TDS
>>
>> 80 = 40 TDS
>>
>> You have some hard water but I have seen higher. EPA drinking std are not
>to exceed 500
>> TDS (IIRC)
>
>Thank Boomer.
>
>Erik,
>Ahh... that more about right. But as for the product from RO should not be
>that high with 100GPD. IIRC from previous post, you have DI unit too. From
>that DI output should be close to non-detectable. From your RO output, that
>seem to be still high. 40TDS is similar to SF water without using any RO
>unit.
>
>You might want to check what the PSI before going into the unit. Do your RO
>have a PSI meter? If so, what it indicating?
>
>CapFusion,...
>

[CapFusion]

"erik" > wrote in message
...
> No DI yet. I'm looking into building one. PVC pipe is cheap :o)
>
> Anyway, 40 ppm TDS may still be high but if I'm getting a 90 to 95 %
> reduction in TDS after the RO should I be expecting better of a CTA
> membrane?
>


When I see 40ppm reading from TDS and want to consider this to be a puriest
source water mix for a reef tank, I would hestitate a bit. But for human
consumption, than, I would say ok. 40ppm reading, will cause algae war /
battle to eternity and normally algae will have the advantage over you. I do
not know much regarding CTA type membrase in RO but as general RO concern,
it should bring down to something like 10ppm or so with TFC or similar
membrane.

With 40ppm, I would suggest using DI unit to further reduce this
filteration. Or change your membrane beside CTA and see if you have better
result without DI unit.

CapFusion,...