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

[revhtree]

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?

 

[Roytrolls247]

luckily I have very low TDS water before it even goes into my Rodi system. I change my filters once a year just to keep a schedule.

 

[KStatefan]

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

Each filter is different

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

How many gallons produced

3. How high is your home TDS?

375

 

[Wolters_88]

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

 

[T-J]

I replace sediment when I can visibly see that it's starting to turn brown. I usually change my carbon at that time as well. DI resin gets replaced when I can see all the color change or if TDS goes above 0 (whichever comes first). Have yet to replace my membrane, as it's less than a year old.
My home TDS is around 450.

 

[stephnjeph]

I replace the membrane every 8-12 months. The carbon and sediment every 3 months or so. Deionization resin is changed as needed and varies due to how much water is being produced. The system splits off before DI-resin into a pressurized tank that's tapped into a separate faucet in our kitchen as well as the water and ice maker in the refrigerator. The deionized water is store d in a standard potable water holding tank until ready to be mixed and/or used.

Edit: Home TDS is 300

 

[Tamberav]

TDS 130s

I change prefilters (sediment and carbon every 6 months).

The spectrapure membrane lasted me 6 years. I change this based on TDS when it’s no longer rejecting the standard it is supposed to.

The super max cap spectrapure Silica/DI lasts me two years. I change this when TDS hits 1.

Remember not all filter cartridges are the same quality or price. I didn’t find the BRS stuff to be great, just cheap.

 

[ying yang]

My tap water tds is as low as 65 and highest ive read is 90 something.
I just changedy rodi filters ( carbon and sediment) for first time last month after 5 years either getting used or sitting unused in rodi unit.
I installed rodi 5 years ago and made 100 litres of water in containers,didnt set up tank so rodi unit stayed unused with water in and after 5 years i binned the water in containers and DID NOT change membrane or filters or di resin in rodi unit or disinfect at all.made rodi water at 0 tds for 370 litre system volume and then changed 25 litres every week for 7 months till tds went to 1 after 7 months,colour change di resin still half good so left original membrane and di resin in for 5 years now.

Im not saying for others to do this as best practice would off been to throw all filters away and replace and disinfect system as bacteria grows in it but bacteria is everywhere was my thinking and no harm so far that i know off.

 

[alton]

1. How often do you have to replace your RO/DI filters? Membrane when it goes over 10ppm, normally at 6 months. My filter for removing Chloromines which is the chloromines blaster from BRS is going on 2 years. The 10" before that where lasting less than a month. I get 3 DI filter changes between 1 Membrane change

2. What's the biggest factors that come into play in exhausting your RO/DI filters? Membrane is heat, I change more in the summer than winter.
3. How high is your home TDS? sometimes 100, sometimes 200, and sometimes 400. The city of San Antonio plays a game called hide the water. When the Local aquifer has plenty they will pump it to other aquifers in other counties. (That is how I get 400). When they need to suppliment the local aquifer the water flows the other way I get between 100 and 200.

 

[Gtinnel]

1. I change pre filters and di about twice a year, maybe a little more.

2. The biggest factor for me is how many gallons I make.

3. I don't have any idea. I only check tds after my membrane and after my di. I've recently started to see a rise in my tds after the membrane so I do need to check my rejection rate, but I haven't yet. I'm going on 2 years on my membrane and I suspect it's time to replace it.

 

[LVReef]

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.

 

[Floyd-]

1. How often do you have to replace your RO/DI filters?
So far I have not changed them in maybe 6 months, Might get a year from them

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

3. How high is your home TDS?
VERY low. Only measured at 25 TDS with a digital tester.

 

[Woodyman]

Talk about a loaded question(s).....

1. How often do you have to replace your RO/DI filters?
which filter? It does vary as well based on usage and season.
Sediment ~ every 2/3 months
Carbon - as its exhausted ~ 2/3 months
Membrane ~2-4 years
DI ~ 3-6 months

each one of these filter/stages should be monitored and changed as needed, different monitoring devices/types for each filter.

Sediment should be pressure based
Carbon should be when you get chlorine bleed through
membrane should be when the rejection % drops below acceptable ranges
DI should be when TDS is registered

2. What's the biggest factors that come into play in exhausting your RO/DI filters?
Source water - if your water comes in at <100 TDS they are going to last significantly longer than someone who has source water at >500 TDS

3. How high is your home TDS?
~300 - 400

 

[Woodyman]

Talk about a loaded question(s).....

1. How often do you have to replace your RO/DI filters?
which filter? It does vary as well based on usage and season.
Sediment ~ every 2/3 months
Carbon - as its exhausted ~ 2/3 months
Membrane ~2-4 years
DI ~ 3-6 months

each one of these filter/stages should be monitored and changed as needed, different monitoring devices/types for each filter.

Sediment should be pressure based
Carbon should be when you get chlorine bleed through
membrane should be when the rejection % drops below acceptable ranges
DI should be when TDS is registered

2. What's the biggest factors that come into play in exhausting your RO/DI filters?
Source water - if your water comes in at <100 TDS they are going to last significantly longer than someone who has source water at >500 TDS

3. How high is your home TDS?
~300 - 400

Highly highly dependent on usage/source water, if your making 1000+ gallons a month and your source water is >500 TDS every 3 months might not be that bad, but if your making 100 gallons a month and your source water is <100 you shouldn't be replacing anything after 3 months.

The most efficient (call it best practice if you want) way to know how often is to often would be to log how many gallons are being produced and your source water temp/TDS throughout the year. If you notice any dramatic changes say you went from changing once a year to every 6 months something may be wrong. Just like our tanks the best way to monitor and know when you have a problem is paying attention to the system and knowing what to look for.

Generally, if you are changing filters more frequently than every 3 months, there might be a problem, but not if your making huge sums of water with high source water TDS. The water in the US and across the world varies greatly but *most* should get at least 3+ months out of sediment, carbon and DI, and a good 1+ years from membranes.

 

[Kodski]

The "time" for each individual person will be different but everyone should be replacing their filters at the same "time."


This sounds like a riddle, but let me explain.

Right here on the packaging states when you should change your carbon block. Since most people who live in the city will have Chloramines in their water, we can assume that you NEED to change your carbon block every 2,000 gallons of water.. Now, this is NOT 2,000 gallons of RO/DI water. This is 2,000 gallons of water PROCESSED. So yes, this includes waste water which makes it a bit more tricky to figure out. To be on the safe side, I'd figure every 1,500 gallons. Now I've never found instruction's on sediment filters, but I'd say every two carbon block filter changes, would be a good base line to change them out even if they don't look dirty yet. I live in an area with a lot of heave minerals in our water, so that may vary. But since the sediment filter cartridge filters water starting from inside out, the second you see brown on the outside of the cartridge means its time for a new one. For the membrane, BRS recommends every 3-6 times you change your other filters, you should replace for membrane. Take that for what you will, but to me that means every three times I change my sediment filter I should change my membrane out.


DI resin of course should be changed out any time you see TDS above 0. Period.

 

[Woodyman]

The "time" for each individual person will be different but everyone should be replacing their filters at the same "time."


This sounds like a riddle, but let me explain.

Right here on the packaging states when you should change your carbon block. Since most people who live in the city will have Chloramines in their water, we can assume that you NEED to change your carbon block every 2,000 gallons of water.. Now, this is NOT 2,000 gallons of RO/DI water. This is 2,000 gallons of water PROCESSED. So yes, this includes waste water which makes it a bit more tricky to figure out. To be on the safe side, I'd figure every 1,500 gallons. Now I've never found instruction's on sediment filters, but I'd say every two carbon block filter changes, would be a good base line to change them out even if they don't look dirty yet. I live in an area with a lot of heave minerals in our water, so that may vary. But since the sediment filter cartridge filters water starting from inside out, the second you see brown on the outside of the cartridge means its time for a new one. For the membrane, BRS recommends every 3-6 times you change your other filters, you should replace for membrane. Take that for what you will, but to me that means every three times I change my sediment filter I should change my membrane out.


DI resin of course should be changed out any time you see TDS above 0. Period.

Don't change it when it's 'brown' it may still have weeks or months of use still left. Sediment filters should be changed when you see a 10% or more reduction in pressure from the 'in' to the 'out' side of the housing. To make this example easy if your incoming pressure to the sediment is '100 psi' (which again just using 100 to make it easy, if your really at 100 that's not good...) you should be changing the sediment filter when your outgoing psi is reading '90 psi'.

The reason behind this is the pressure drops as the filter clogs up with material. So even though it turns brown if your 'out' psi is still pretty close to your 'in' psi your just wasting filters. I go with 10%, some go with a 10/20 or even 30 psi drop so using the example pressure above they wouldn't change the filter until it drops to 70, 80, or 90 psi.

I got the 10% recommendation from an engineer with Spectrapure, and I've followed that.

 

[Hydrored]

Sediment monthly, Carbon blocks every 3 months, DI and membranes every 6 months, chloramine monsters (2) rotate every 6 months and replace once each turns a year old (offset by 6 months)

375 TDS, chloramines, and whatever nasty red stuff that's in our Texas water

Rather it's needed or not I stick to that schedule, a small cost to me as it relates to base water quality.

@SBB Corals as Shane may have some value to add to this discussion

 

[mattdg]

RO - Yearly

DI resin is in 2 side by side chambers. When one is depleted (color changing) I scoop it out and add new.

Sediment - when it starts to show color

Carbon Block - every two to three months

 

[lagnew904]

My Florida water stays between 200-240 TDS. Only have a 32 gallon display 41 gallon total.

So far 5 gallon water change every other week has been working well. This will most likely increase with addition of new coral and fish. I'm about 100 gallons produced on the BRS 5 stage. If I can get a year before replacement I'll be happy.

 

[OneSockERock]

Voted 3 months or less which is how fast I was burning through my old Aquatic Life RO buddie DI resin. Jury is still out on how often I'll have to replace my new 5 stage BRS filters.

Usage is definitely the biggest factor. Certainly doesn't help when I forget and leave the container over flowing into the utility sink. Trying to get better at that by setting alarms on my phone with the new unit.

~325 TDS out of the tap

When the DI resin was exhausted on the RO Buddie my RODI would actually test positive for total ammonia around 0.8 - 1ppm. So I'm guessing the RO buddie carbon block was toast at 3 months as well. My city adds chloramines at up to 3ppm according to the water quality report and ammonia too. Total ammonia concentration is not stated on the report but I'm guessing around 1ppm based on my tests. Started switching out the RO buddie carbon filters at the same time as the DI for the last few cycles before I retired the unit. I'm only making ~15gal a week for water changes and top off for all of my tanks.

Recently switched over to a 75GPD basic 5 stage BRS RODI unit hoping I would get better filter life and to add an additional carbon block to deal with the chloramines. It's been about a month and a half and my DI resin is about 1/3 exhausted so it looks like it's working in my favor, maybe slightly?

Question for all of you more experienced RODI users, is it normal to have to replace the DI resin faster than the carbon blocks?

I plan on grabbing some total/free chlorine test strips when my DI is exhausted and see what's coming out of my carbon blocks at that point to determine when I need to be changing those out, but any advice in the meantime would be much appreciated.