tds readings
 

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

tds readings
 

"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,...

tds readings
 

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

tds readings
 

"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 ;-)

tds readings
 

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

tds readings
 

"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?

tds readings
 

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?

tds readings
 

"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 :-))

tds readings
 

"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,...

tds readings
 

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 :-))