WTF... RO/DI putting out high TDS!!! help please...

[Kimo]

If you don't change your carbon filter regularly the chlorine that gets to the membrane will ruin it - I have that problem myself. I used up a DI cart (good for 6800 gallons) making about 60 gallons of water.

I am adding a second carbon filter to my RO/DI and replacing my membrane with a 75 gallon per day one due to its high rejection rate (100 gal/day rejects 90%, 75 gal/day rejects 98%)

HTH,

Jamie

 

[Anonymous]

Back flushing kit is not necessary, but can be a good thing to have. I have one on my filter, and last time I used it was about a year ago... lazy bastard...

I strongly suggest you use TDS or other monitoring device when using DI. The color change is a poor indicator, and you should never relies on it for the resin capacity. Many people use multiple stage DI just to catch the craps as the first stage of DI get used up. I have 3 stages, FWIW. (Did I tell you I am lazy?)

 

[jandree22]

Alright, I flushed my RO for >1hr then tested the water coming directly out of the RO membrane... it's 32ppm. Maybe I'm wrong, but IMO that's enough proof for me to warrant the new membrane.

 

[FragMaster]

Yes it is! Replace that bad boy.

 

[jandree22]

Yes it is! Replace that bad boy.

Currently in possession of the USPS :wink:

 

[FragMaster]

SWEET!

 

[Anonymous]

What is the TDS without the DI? That is, just the RO alone?

 

[Anonymous]

What is the TDS without the DI? That is, just the RO alone?

Alright, I flushed my RO for >1hr then tested the water coming directly out of the RO membrane... it's 32ppm. Maybe I'm wrong, but IMO that's enough proof for me to warrant the new membrane.

_________________
marijuana plants

 

[howdydo]

If you don't change your carbon filter regularly the chlorine that gets to the membrane will ruin it - I have that problem myself. I used up a DI cart (good for 6800 gallons) making about 60 gallons of water.

It's not 6800 gallons, it 6800 total ppm of TDS absorbed per a 1 pound mixed bed DI resin cartridge.

May have been a mis- type on your part, but didn't want people trying to get 6800 gallons out of one!

And to the OP, what is real important to know is the rejection rate of the membrane. Find out your tap water TDS, then your RO only TDS. Most 50/75 gpd membranes have a 96-98% rejection, so you should be in the 2-4ppm TDS range for every 100 ppm TDS of your source water.

Take care, Howdydo!

 

[jandree22]

What is the TDS without the DI? That is, just the RO alone?

Alright, I flushed my RO for >1hr then tested the water coming directly out of the RO membrane... it's 32ppm. Maybe I'm wrong, but IMO that's enough proof for me to warrant the new membrane.

^-- Yah, what that guy said :lol:

 

[jandree22]

And to the OP, what is real important to know is the rejection rate of the membrane. Find out your tap water TDS, then your RO only TDS. Most 50/75 gpd membranes have a 96-98% rejection, so you should be in the 2-4ppm TDS range for every 100 ppm TDS of your source water.

This is a good point I didn't necessarily take into consideration yet... my membrane is 98% rejection and my input TDS is about 250ppm, so I should be in like the 4-6ppm range output. :roll: :lol:

 

[Anonymous]

I saw a dramatic decrease in TDS output when I switched to a Hi_Silicate removal membrane (60 gpd).

Tap - 350
RO - 4
DI1 - 0
DI2 - 0
_________________
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[howdydo]

And to the OP, what is real important to know is the rejection rate of the membrane. Find out your tap water TDS, then your RO only TDS. Most 50/75 gpd membranes have a 96-98% rejection, so you should be in the 2-4ppm TDS range for every 100 ppm TDS of your source water.

This is a good point I didn't necessarily take into consideration yet... my membrane is 98% rejection and my input TDS is about 250ppm, so I should be in like the 4-6ppm range output. :roll: :lol:

Well, real world vs. manufactuers numbers will realistically put you at between 12-15, not 4-6. Even 10ppm would be great as you'll get about 680 gallons of 0 tds water from you DI cartridge.

Rob Reef Keeper, do you have a link to where you purchased this Hi S membrane?

Take care - Howdy

 

[FragMaster]

readings,flow rates ,and longetivity data are produced by the manufacturer under contolled conditions. Cooler water, cleaner water, and frequent maintenance.
We will never see those numbers other than possibly the 1st run of good water after the initial flush/break in.

 

[Anonymous]

Rob Reef Keeper, do you have a link to where you purchased this Hi S membrane?

http://spectrapure.com/St_replac_p3.htm#silica
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[jandree22]

Well, I received the new membrane yesterday and swapped in all 5 new stages in this morning and hooked 'er back up. The water I pulled for testing was still in the "new membrane waste" batch, but was only 4PPM instead of like 40 It's also producing A LOT slower than with the old membrane, so that makes me wonder if there was some kind of leak in it?

Right now it's bypassing the DI until the first 5 gallons are wasted, but I have no doubt it'll get down to 0-1PPM after that. Now we'll see if this helps my freekin cyano problem :evil:

Thanks for all the help guys!


UPDATE: It's official... addition of the DI = 0ppm TDS... w00t!

 

[trigger0214]

trigger0214 wrote:
Did you sanitze the system when you installed the new filters? You should be able to run some hydrogen peroxide through there with no damage to the TF membrane.


Nope, sure didn't sanitize. How the heck do you get H2O2 through the membrane... specifically, how do you pressure it?

I guess it'd be a big no-no to give it a quick shot of straight chlorinated tap water to kill the bacteria, wouldn't it?

Soak it.....and/or, pull off the output and back siphon.


To get really geeky....check the following:

http://www.drshannonco.com/download/res ... 0membrane'

 

[trigger0214]

in regards to your Cyano - I started using a product called Marine S.A.T. Essenitally bacteria to out compete your cyano. Knocked mine right out.

 

[jandree22]

in regards to your Cyano - I started using a product called Marine S.A.T. Essenitally bacteria to out compete your cyano. Knocked mine right out.

...for good? My only fear with these solutions is that it knocks it out for a week or even a few weeks, but then comes right back. If they're effective for the long term, I'd definately look into it.

 

[trigger0214]

I did just start (about the last 10 weeks or so). The directions call for 5 weekly doses, then switching to monthly. I did three, then went to bi-weekly and now tri-iweekly. I am trying to 'wean' the system off of it. So far, so good.

Grain of salt - i did just get a purple urchin (last two weeks - for green hair), but the stuff does seem to work. Common sence says it SHOULD keep a viable culture in the tank (as long as there food to be had).

I have heard off people having very good luck with that red-slime away stuff.