How to know when your RODI needs new filters

[dcforester1]

I have an AWI 5StageTyphoonIII Sysytem, It has 4 canisters on the bottom, and a smaller one on the top. I have been at 0TDS for the last 9mo, the unit is alittle over a year old. The last time I checked I was getting 4TDS, so I am assumming the filters are getting old.

My questions are,

Do you replace all 4/5 of them at the same time?

How do you know which one to change?

Can you go from a 75gpd to 100gpd membrane?

The first filter is all brown. The second and third, look to be the same, and they look the same as they did when they were new. The last one looks like a gel filled tube, and the bottom 3-4in of it are missing. It doesnt look like the others. The fifth one is on top. I am assuming this is the DI chamber. Does this one have a catridge, or do you fill it with those beads? Or do you not know until you take it apart?

Any insight on how this works, and how I should be replacing the filters would be greatly appreciated.
Thanks Derek

 

[snowmaker]

Can you go from a 75gpd to 100gpd membrane?

You can piggy back another 75 gpd on to your existing ro membrane if you have (I think) at least 65 psi.

If you have a DI canister, it might be all you need to change (just the resin), and can flush (clean) the existing RO membrane.

 

[afboundguy]

Usually you can tell if the filters before the RO membrane needs changing by a decrease in pressure (if you have a pressure guage) The DI cartridge is filled with those beads and usually the one all the way on the right. The one on top is usually the RO membrane...

Do you have a flush kit? That might help clean up the RO membrane.

 

[emabie]

Your system contains 5 filters:

3 prefilters - The first 3 in the water line. They filter the water to remove the larger stuff before it goes to the membrane.

1 Reverse osmosos membrane - This is the filter that is usually on top going horizontal. Once the water has been prefiltered to goes tot he membrane. The membrane has 2 outputs, one goes to a waste line that also has a flow restricter on it. This restricter forces water through the membrane and then to the clean RO output. The RO will usually get your TDS to under about 10 or less.

1 DE-Ionization filer - This last filter cartride is the one that you see that looks like 3-4'' are missing. Most will change from a dark color to an almost pink or tranparent color when used up. The DI removes the last of the smallest contaminants from the water.

Typically you change the prefilters when you notice that the output has slowed down due to them clogging up. I do mine about 6months to a year.

The RO membrane can last a very long time and only needs to be replaced when it gets clogged and stops producing clean water and makes too much waste.

The DI will get used up and you will see the color change .Typically when the DI is getting used up you will see your TDS creep up slowly.

As someone mentioned you should flush the membrane regularly. This is done by removing the flow restricter and allows all the water to flow over the menbrane to the waste output. This washes it otu and really helps prolong the life. Most RO units have a flush valve or kit available. I recomend adding it if yours does not have it allready.

 

[emabie]

Can you go from a 75gpd to 100gpd membrane?

You can replace the membrane to a higher GPD but you will also need to replace the flow restricter to match the new membrane size.

The other option is to run 2 membranes in parallel as was mentioned above.

I believe that the higher the GPD rating the higher TDS out you get from the membrane. This means the DI has to do more work and will need to be replaced more often

 

[MikeG]

Emabie had a great explanation so I won't add anything to it. I do want to mention that timing of filter changes is very dependent on source water. My tap has very high TDS, especially sediments. I replace my sediment filters every 2-3 months and my carbon filter about every 4-5 months due to them getting clogged. My DI gets replaced every 5-6 months. Even with that, my RO membrane seems to last about 4 years or so.

Best way to know When to replace RO and DI is to check TDS after RO and DI chambers. If you have a duel inline TDS meter, I always put the in line between the RO and DI and the out line after the DI. I never use it to monitor the tap. If you have a hand held you would have to disconnect the line going into the DI canister to see how the RO membrane is doing.

 

[emabie]

Here is what I use and what MikeG is talking about in a dual inline TDS meter.

http://cgi.ebay.com/HM-DM-1-Inline-...all_Kitchen_Appliances_US?hash=item35a45a77bb

+1 on the tap water determining how often you change the filters. I have well water with a TDS of about 110 -125.

 

[MikeG]

Here is what I use and what MikeG is talking about in a dual inline TDS meter.

http://cgi.ebay.com/HM-DM-1-Inline-...all_Kitchen_Appliances_US?hash=item35a45a77bb

+1 on the tap water determining how often you change the filters. I have well water with a TDS of about 110 -125.

And for comparison, my TDS can get upwards of 450 in the summer.

 

[dcforester1]

Thanks guys, I think I am following, except i thought the Di was the small one on top, I might be wrong, but not sure. I can see the first 3, they do look like they are some type of sediment filters, and the first one is dirty. Is it a waste of time buying a replacement set of filters, or do you just buy the individual ones? If the the DI is a catridge, should it be replaced with the loose resin, if I get a canister for it to go in? I do have a flush kit, and use it everytime I make water. I am going to have to figure this out.
Thanks Again Derek

 

[MikeG]

Refillable DI resin is the way to go if you have a refillable container. I bought a package from Air water ice not too long ago with the container and enough resin to refil 4 times and it was like $40. I was use to paying about $30 for one cartridge.

Edit: ok it was $46 dollars http://www.airwaterice.com/product/REFILLDIPACK/DI_Refillable_kit.html

 

[dcforester1]

Thanks Mike, Is that a regular full size canister, or the smaller one on top? Do you buy the filters seperate, just the ones you need, or a whole set at a time? Thanks for all the help?
Derek

 

[MikeG]

That is a regular canister, fits in the same type of container that the prefilters are in. In most cases the small container on the top is the RO membrane.

As far as filter I normally buy a set with say 2 sedimant, 2 carbon, and 1 DI (until I switched to the refillable DI). I have only replaced the RO once in the 6 or so years I have run the filter. Then I just buy additional prefilters as needed if I run out.

One easy way to find out which is the RO membrane is the container will have one line going in (feed) and 2 coming out (waste and clean water) All others will have one in one out.

 

[number1gsxxr]

The DI can be a cartridge or loose resin. Here is a picture of what a typical DI resin cartridge might look like.

 

[number1gsxxr]

The resin might also be in this type of canister. It's a bit smaller than the larger ones.

 

[dcforester1]

The set up I have has one small one on top. It looks like picture 14, but it is white you cant see in it. So is that the DI? I would post a link, but I dont know how. It is the AWI Typoon III. Its a 5 stage unit, I dont mean to be a PITA, but I dont want to waste my money on something I dont need. I really appreciate the help.
Derek

 

[MikeG]

The set up I have has one small one on top. It looks like picture 14, but it is white you cant see in it. So is that the DI? I would post a link, but I dont know how. It is the AWI Typoon III. Its a 5 stage unit, I dont mean to be a PITA, but I dont want to waste my money on something I dont need. I really appreciate the help.
Derek

How many tubes going in and out of that white cylinder?

 

[dcforester1]

I dont know, that would require me to get off my a$$, and look. LOL I will have to check it in the morning. I have it in a spot where I never took into consideration that I would have to remove the canisters. I will check it out. Thanks for all your help

 

[emabie]

To find the DI just follow the line from the final clean water output back, the water output always comes from the DI filter as it's last in the 5 stages.

TO find the RO membrane filter follow the waste line back. The RO is the only one that has a waste line. It has one in and 2 outs, The waste and the one that feeds the DI.

Thats how a typical setup is on a multi stage RO/DI.

Send a pics of yours and I will try to identify the parts.

 

[Rob]

pressure gauge

where does that fall into place? I want to add one to my 5 stage.......

 

[emabie]

where does that fall into place? I want to add one to my 5 stage.......

You can put a pressure guage inline anywhere. I have one on the input so I can monitor the incoming well water pressure.

ANother spot would be to monitor the pressure before the membrane.

Go to HD and get a water pressure gauge and a T connection for the size plastic tubing you have in your system. Installs in 5 minutes.