# problem with ro/di?



## monk21 (Dec 5, 2012)

Hi,

I have the pure flo ro/di and the reading I get from the tds are

tap water: 134 ppm
ro/di water: 80 ppm

80 is still too high huh? What can be going wrong? Any suggestions?


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## rburns24 (Jan 31, 2011)

You need to change your di cartridge.


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## monk21 (Dec 5, 2012)

rburns24 said:


> You need to change your di cartridge.


What makes you think di? I am afraid about membrane. Truth is that I tried some water without di and it was still high. But I didn't let it run for long. And again, if the water leaves ro perfect clean, is it possible that an old di filter ruins it back?

PS it is the first time I am using a rodi.


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## jkoot (Apr 17, 2012)

If your getting 80 ppm than your membrane needs to be replaced for sure. Your first stages and membrane should be bringing the TDS to idealy under 5 ppm. The DI just polishes and brings it down to 0 ppm. 

I would recommend changing all of the filters on the unit and starting fresh.

>jason


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## monk21 (Dec 5, 2012)

jkoot said:


> If your getting 80 ppm than your membrane needs to be replaced for sure. Your first stages and membrane should be bringing the TDS to idealy under 5 ppm. The DI just polishes and brings it down to 0 ppm.
> 
> I would recommend changing all of the filters on the unit and starting fresh.
> 
> >jason


Thanks for the info. Is there any other way to see if it is indeed the membrane? It is too expensive to just risk it like that! Also, if I dont use a di at all, will I be ok or I still need it? Last question, for a fowlr 20g, do I really need all that?

thanks


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## J_T (Mar 25, 2011)

Is this a new RO unit? Or a used one?

Work backwards. 

TDS from the DI is...
TDS from the membrane is...

It should be really low after the membrane. The DI sucks up the last of the TDS.

Flush the membrane, 15-30 mins. Then run the RO for 30-60 mins. Now what are the readings?


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## monk21 (Dec 5, 2012)

J_T said:


> Is this a new RO unit? Or a used one?
> 
> Work backwards.
> 
> ...


Flushing is swapping good and bad hoses and letting it just run?

The system is used. The membrane stayed inactive but wet for 6 months. That is why I am almost sure it is its fault.

Last thing (on top of previous questions) since we are on the subject of water changes. What method do u use to get the water from the bucket and into the tank? For freshwater I use the python so I am unprepared for this o e


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## J_T (Mar 25, 2011)

Most use an auto top off. It will add the water slowly, as needed to the system to top it off.

As for the RO unit. Do a google search for membrane flushing kits. Then look to see if you have one. If not, you can make one easy enough from parts at HD. Just need two T's, and a valve. If you look around, you can find nicer spliters, and that is what I did with mine.


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## monk21 (Dec 5, 2012)

Update and further help required

I went and bought and replaced the membrane, carbon block and Sediment. I didn't find di filter yet so I didn't replace it but I am not using it now so I see what the ro alone is doing.

1) I am getting 15 with the tds after the ro. Is it good or bad? Is it ok to keep going with this or I really need the di? Will the tds fall further after I have filtered more gallons or not (I have done like 2 gallons until now.

2) for these 2 gallons it needed a bit more than 2 hours. The membrane is supposed to be a 50gpd membrane. What can be wrong?

Thanks


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## 50seven (Feb 14, 2010)

1. 15 TDs isn't bad. Especially with a fowlr tank you'll be fine. A DI resin bed will remove the rest. 

2. Could be improperly matched up with the flow restrictor causing the disparity. But unless you have a monster tank, do you really need 50 GPD?

Sent from my Galaxy Nexus using Tapatalk 2


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## J_T (Mar 25, 2011)

Water pressure. I am betting that the flow restrictor, and water pressure is the reason for low out put.



New membranes need a good flushing to remove the coating that keeps it fresh. Once that is gone, the tds may drop more. The coating coming off will show as tds when you check.



Also... Have you tested your tds meter? Is is calibrated?





Sent from my HTC 8 using Tapatalk


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## monk21 (Dec 5, 2012)

50seven said:


> 1. 15 TDs isn't bad. Especially with a fowlr tank you'll be fine. A DI resin bed will remove the rest.
> 
> 2. Could be improperly matched up with the flow restrictor causing the disparity. But unless you have a monster tank, do you really need 50 GPD?
> 
> Sent from my Galaxy Nexus using Tapatalk 2


1. I will have corals soon as I am buying a full setup and upgrading to 75 gallons. You think for corals I must surely get the di?

2. Where exactly is that and how can I check it? I will use it mostly in a 75g. Of course even then I will not use more than 15g every couple of weeks but I am still worried why it is not working properly.

3. How can I store rodi water to use later?


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## 50seven (Feb 14, 2010)

1. You'll be fine for starters. But keep it in the back of your mind for the next time you make an order from MOPS or BRS that you add a DI resin to your order. 

2. I have the same issue of disparity with rated volumes but has never impacted my water needs. I have a 90g with a total of 200g system water volume. 

3. Any sealable food grade plastic container. 

HTH...




Sent from my Galaxy Nexus using Tapatalk 2


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## monk21 (Dec 5, 2012)

50seven said:


> 1. You'll be fine for starters. But keep it in the back of your mind for the next time you make an order from MOPS or BRS that you add a DI resin to your order.
> 
> 2. I have the same issue of disparity with rated volumes but has never impacted my water needs. I have a 90g with a total of 200g system water volume.
> 
> ...


thanks for the reply,

1. What is MOPS and BRS?
2. Then I should not worry about it
3. Does it need to be sealable? And I just leave the water in there? For how long? Do I need a powerhead to move the water? Any specific ones that Canadian Tire is selling for example so I don't buy a wrong one?
4. Then what is an easy and good way to transfer this water in the tank?

What is HTH?


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## 50seven (Feb 14, 2010)

Mail Order Pet Supplies (.com) -nice guy out of Hamilton area 

Bulk Reef Supplies -big American company / website

Hope This Helps



Sent from my Galaxy Nexus using Tapatalk 2


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## monk21 (Dec 5, 2012)

Oh ok Thanks! I bought them from a guy around here and he didn't have a di. If i find a cheap one somewhere I will def. buy one


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