RO/DI Filters: How often is too often to have to replace them?

[Freenow54]

After installing my RO system my tds was about 5. On the advice of a member I added a DI filter. after 6 months it still sits at zero. My RO filters are to be changed 6 months, and the other 1 year

 

[West1]

Hi and hello.i only have a dual inline tds meter but you can buy a triple inline tds meter so can check tds at 3 stages so guess this is how people can check ....
1,incoming tap water
2.after membrane
3.product water after di resin
If checked after sediment and carbon would have to disconnect the tds meter and place after what stage you want and check ( would have to have connectors or have longer tubing and remove a piece tubing where tds meter was while checking another place or run water into a bucket.

I see, I forgot about the in-line digital meters! Always heard they were not reliable so I got myself an HM Digital COM-100
Thanks for clearing that up for me

 

[Freenow54]

Forgot to say I make about 45 gallons a week with my zero waste watts system. I love it.

 

[Woodyman]

I see, I forgot about the in-line digital meters! Always heard they were not reliable so I got myself a Four E scientific pipettor.
Thanks for clearing that up for me

I have found the HM meters to be very accurate and minimal drift over time. Checking the calibration is tedious the first time because you need the proper equipment first otherwise you won't be accurately checking and you will needlessly calibrate it to the wrong number.. make sure you follow the directions and only check/calibrate the unit with flow. It can be pricey since those small calibration bottles are about 7/8 bucks each and I've found at least with my setup I need 3 bottles to verify my meters. I typically check once a year and I've only had to correct one of the my 4 meters and only by 2ppm. The units I have are about 4 years old so I've checked them 5 times, initially and every year since.

 

[lapin]

page 5 ?

1. How often do you have to replace your RO/DI filters?
Sediment filters and charcoal every month when they turn brownish green.
RO last changed 2 years ago.
DI resin; 3 stage set up, going on 2 years now, and stage 3 is not even turning brown at all.
I make about 450 gallons a month

2. What's the biggest factors that come into play in exhausting your RO/DI filters?
Sediment. Rain water tank has a lot of pollen from an oak tree over our roof. Makes for a tea like tint to our water.

3. How high is your home TDS?
TDS 11 today

 

[Aeb1419]

I change everything out or at least suspect something needs changing when my TDS meter reads more than 0. Is that ok? Is there more to this that I am not considering?

 

[Mike1970]

I change my ro/di filters when my TDS reads 1

 

[Appoloreefer]

Depending on the TDS of your water, how much water you're making and other factors you could be replacing your RO/DI filters more often than you want to. But how often is too often? Let's poll the community today and see what others have to say!

1. How often do you have to replace your RO/DI filters?

2. What's the biggest factors that come into play in exhausting your RO/DI filters?

3. How high is your home TDS?

I change them anywhere between 3 and 6 months depending

 

[flyfisher2]

I just redid my entire Ro/DI system with the help of fellow reefers here on R2R. Previously I was burning through Membranes like candy. Went through 4 in about a year. As it stands we've brought the system indoors and its going on three months soon. As it stands the Tap water is testing at about 161. Post Membrane is averaging at about 6TDS. and Post DI 0. I'm producing an average of 70 gallons usable water weekly and I've changed DI about every 5-6 weeks. I'm not entirely sure what the ratio of waste water is on my present membrane.

 

[Woodyman]

I just redid my entire Ro/DI system with the help of fellow reefers here on R2R. Previously I was burning through Membranes like candy. Went through 4 in about a year. As it stands we've brought the system indoors and its going on three months soon. As it stands the Tap water is testing at about 161. Post Membrane is averaging at about 6TDS. and Post DI 0. I'm producing an average of 70 gallons usable water weekly and I've changed DI about every 5-6 weeks. I'm not entirely sure what the ratio of waste water is on my present membrane.

It's really been almost 3 months.... Geez where has this summer gone..

 

[BBN Reefer]

I change them when they need changing... It's not a function of time but the quality of the input and the volume of the output. Here's my guide guide

Sediment When the pressure drops by 10-15% or I can see it's dirty. I have a water softener so it rarely gets dirty
Carbon I use the Chlorine/Chloramine strips on the RO reject once a month after 6 months. If I see any, I replace both with the BRS carbon filters
RO The TDS coming out of the RO membrane is 4ppm under normal circumstances for my system. If the TDS rise or the output diminishes enough that I notice, I change it. Usually around the 2 year mark.
DI When it's depleted lol. I use the BRS 3 DI setup.

What strips are you using? I looked at some but they got bad reviews. Does DI remove cloramine if the carbon is exhausted?

 

[ClownWrangler]

RODI system with re-circulation pump running at 80PSI I designed and built myself.
Replaced boost pump once.
Original membrane is going on 10 years old and still has good rejection ratio and performance.
5 years @ 450-500ppm TDS (southern CA) and 1:1 P/W ratio and 5 years at 42ppm TDS (PNW) 1:1 P/W ratio
Replace carbon filter once every six months or so.
Current output is 5GPH and 1-2ppm TDS. I don't run DI resin at the moment.

 

[lefkonj]

What is your whole house filter? What media is inside it?

It is a foam pad with carbon in it. Basically sediment down to 25 microns. My first stage of the RodI never ever changes color.

 

[ClownWrangler]

What strips are you using? I looked at some but they got bad reviews. Does DI remove cloramine if the carbon is exhausted?

It may absorb some, but it will destroy your DI resin quickly and its not good for an RO membrane either. The activated carbon removes volatile organic compounds from chloramines and the DI resin removes any cations and anions from ionic compounds that make it through the RO membrane, so one is not interchangeable with the other. Chloramines are tricky. They can exist as inorganic or organic compounds, but break down in to VOCs as well. So its the job of the carbon, not the DI resin to remove them.

The best thing to do is to install a flow meter with an alarm to remind you to replace the carbon filter or just replace it well before you need to to be safe. Figuring out how often to replace it is another thing. It depends on the chloramine content of the water and the filter specs.

 

[Biglew11]

Great thread!

I change membrane every 6-8 months.
Sediment and carbon once a month or approximately every 200-250 gallons.
Idk my tap TDS.

I need to read everyone’s post, I may be going overboard!

How is everyone testing tds at each stage?
Does each stage have a T w/a shutoff valve or is everyone going through the hassle of removing the IN-Line and testing?

Forgot to mention I also have two 2stage in line tds meters in my system. First meter first stage at the inlet 2nd stage between ro and first di stage. Second meter first stage between the 2nd and 3rd di stage. This tells me if the cation or the anion is used up. And the 2nd stage of the second meter is the final output stage. I usually change anion when I see 1tds between my 2nd and 3rd stage but the 3rd stage mixed bed can take care of a couple tds for a while if I get lazy. Using these 4 stages gives me alot of info on how the different stages are performing.

To bad there's not an easy way to measure the chlorine chloramine levels inline.

 

[MnFish1]

1. How often do you have to replace your RO/DI filters?

Perhaps every 6 months - when the TDS is above zero. I do not change it otherwise (I change the resin when the color indicates it no matter what the TDS). One issue with this question - is 'how much water is your tank. For example - a nano tank RODI would not need to be changed anywhere near as often as a 500 gallon tank....

2. What's the biggest factors that come into play in exhausting your RO/DI filters?

Not sure what this means

3. How high is your home TDS?

About 80-100

 

[Buckeye Hydro Verified Sponsor]

Forgot to mention I also have two 2stage in line tds meters in my system. First meter first stage at the inlet 2nd stage between ro and first di stage. Second meter first stage between the 2nd and 3rd di stage. This tells me if the cation or the anion is used up. And the 2nd stage of the second meter is the final output stage. I usually change anion when I see 1tds between my 2nd and 3rd stage but the 3rd stage mixed bed can take care of a couple tds for a while if I get lazy. Using these 4 stages gives me alot of info on how the different stages are performing.

To bad there's not an easy way to measure the chlorine chloramine levels inline.

Why in the world are you changing membranes so often?

 

[guysmiley]

Membrane is yearly, carbon is every six months and the sedement is every month. My tap TDS is 450

i bought a booster buddy and get better millage now

 

[Biglew11]

Why in the world are you changing membranes so often?

I'm not, my membranes are about 2 years old and still put out 2-3 tds. I'm running around 90 psi at the membrane. I only change anion di resin once I get about 1-2 tds after that stage. I haven't had to change cation yet. I should add I make about 45 gallons a week. I have 4 tds sensors to tell me how everything is performing. Only if something is not performing up to par will I change stuff.

 

[Buckeye Hydro Verified Sponsor]

I'm not, my membranes are about 2 years old and still put out 2-3 tds. I only change anion di resin once I get about 1-2 tds after that stage. I haven't had to change cation yet. I should add I make about 45 gallons a week. I have 4 tds sensors to tell me how everything is performing. Only if something is not performing up to par will I change stuff.

My mistake. "West1" that said he "change[d] membrane every 6-8 months.