TDS high the lower but not low enough

faulkincanyon · 10/10/2015, 02:35 PM

I have a rodi unit from buckeye hydro and have new membrane carbon block sediment filter but resin has slightly changed color in very bottom of canister. My tap water is about 590 TDS and I am getting about 80 TDS out. Could it just be exhausted resin even though only about 1/16 has changed color. The unit did sit for about a year unused so not sure if that could matter. I know my tap is really high so I am getting good improvement just not perfect, any advice?

azjohnny · 10/10/2015, 03:51 PM

Don't go by the color of the DI cartridge, it is not accurate. you do not have a very good rejection rate. for 590 TDS the post membrane levels should be around 6-12 ppm

What is your feed water pressure?

faulkincanyon · 10/10/2015, 03:58 PM

I just checked in a new plastic container and it is actually now showing 8.

faulkincanyon · 10/10/2015, 03:59 PM

I guess the container I was using previously must not be as I clean as I thought!

faulkincanyon · 10/10/2015, 04:05 PM

I'm not real experienced with this rodi stuff but the guage on the rt side of unit shows about 60psi.

azjohnny · 10/10/2015, 04:09 PM

60 psi is the minimum I would run a RO/DI at

Is the 8 ppm after the membrane or the DI?

faulkincanyon · 10/10/2015, 04:45 PM

After di...im confused though because there is a silver screw I can twist and it will adjust the psi on guage

faulkincanyon · 10/10/2015, 04:49 PM

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faulkincanyon · 10/10/2015, 04:50 PM

Does that need to be wide open or adjusted to get desired psi?

azjohnny · 10/11/2015, 09:06 AM

I am not familiar with the system you have with the metal adjustment screw. I would contact Russ @ Buckeye. It looks like the blue valve is some sort of bypass. With my Maxcap I have 1 pressure gauge and it is for the incoming feed water

Try testing your water before the DI. 8 ppm after the DI is too much, if it reads higher than 0 ppm it needs to be replaced. 8 ppm before the DI would be good considering your feed water TDS

Buckeye Hydro · 10/12/2015, 03:57 AM

That's an older system you have there.

Use that adjustable flow restrictor to adjust the waste water to purified water ratio to about 4 to 1, paying no attention to the pressure gauge. Once you have that ratio set, THEN look at the gauge and see what you have.

REPEAT: Do not use the needle valve as a way to adjust pressure!

Russ

faulkincanyon · 10/12/2015, 06:46 PM

Ok thanks for the help!

kinnadian · 10/12/2015, 06:54 PM

DI resin sitting there open to oxygen with water in it etc will likely be expired after a year.

Most DI resin only has a 1-2 year shelf life assuming it is completely sealed.

10/10/2015, 02:35 PM	#1
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	TDS high the lower but not low enough I have a rodi unit from buckeye hydro and have new membrane carbon block sediment filter but resin has slightly changed color in very bottom of canister. My tap water is about 590 TDS and I am getting about 80 TDS out. Could it just be exhausted resin even though only about 1/16 has changed color. The unit did sit for about a year unused so not sure if that could matter. I know my tap is really high so I am getting good improvement just not perfect, any advice?

10/10/2015, 04:49 PM	#8
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	[IMG][/IMG]

10/10/2015, 03:51 PM	#2
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	Don't go by the color of the DI cartridge, it is not accurate. you do not have a very good rejection rate. for 590 TDS the post membrane levels should be around 6-12 ppm What is your feed water pressure?

10/10/2015, 03:58 PM	#3
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	I just checked in a new plastic container and it is actually now showing 8.

10/10/2015, 03:59 PM	#4
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	I guess the container I was using previously must not be as I clean as I thought!

10/10/2015, 04:05 PM	#5
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	I'm not real experienced with this rodi stuff but the guage on the rt side of unit shows about 60psi.

10/10/2015, 04:09 PM	#6
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	60 psi is the minimum I would run a RO/DI at Is the 8 ppm after the membrane or the DI?

10/10/2015, 04:45 PM	#7
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	After di...im confused though because there is a silver screw I can twist and it will adjust the psi on guage

10/10/2015, 04:50 PM	#9
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	Does that need to be wide open or adjusted to get desired psi?

10/11/2015, 09:06 AM	#10
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	I am not familiar with the system you have with the metal adjustment screw. I would contact Russ @ Buckeye. It looks like the blue valve is some sort of bypass. With my Maxcap I have 1 pressure gauge and it is for the incoming feed water Try testing your water before the DI. 8 ppm after the DI is too much, if it reads higher than 0 ppm it needs to be replaced. 8 ppm before the DI would be good considering your feed water TDS

10/12/2015, 03:57 AM	#11
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	That's an older system you have there. Use that adjustable flow restrictor to adjust the waste water to purified water ratio to about 4 to 1, paying no attention to the pressure gauge. Once you have that ratio set, THEN look at the gauge and see what you have. REPEAT: Do not use the needle valve as a way to adjust pressure! Russ

10/12/2015, 06:46 PM	#12
faulkincanyon Registered Member Join Date: May 2007 Location: Lubbock,TX Posts: 523	Ok thanks for the help!

10/12/2015, 06:54 PM	#13
kinnadian Registered Member Join Date: Mar 2014 Posts: 187	DI resin sitting there open to oxygen with water in it etc will likely be expired after a year. Most DI resin only has a 1-2 year shelf life assuming it is completely sealed.