How often do you replace RODI filter media?

[Oshengems]

Hello everyone,

Just curious how often do you guys change your Filters media ? I have a 4 stage RODI from BRS I been using since the start of the tank March 10, 2017! I have yet up to date 09/12/18 replaced any of the media, the micron sediment, carbon or DI resign. I bought a Dual TDS reader and some replacements to find out I’m still gettin zero readings from this unit both from the membrane and the output line.

Should I hold off replacing them and wait until I see at least 1 reading on the out line or just replace it?

My cold tap waters TDS was 46 going into the filter.

 

[lapin]

I think you could sell your tap water. 1.5 years must be some kinda record.

 

[WVNed]

Today my TDS out went from 0 to 1 and I ordered new filters.

 

[miPapareef]

6 stage BRS here.

Replace 1 of 2 DI media every 3 months even through I get 0 tds after first and 0 after second. Just do it because the color change looks like it could use it.

Replace the carbon blocks and sediment filter every 6 months even though tds after RO always reads 2.

 

[PDR]

I'm in the same boat as you. My tap has a tds in the 30's and I can easily go well over a year without needing to replace any of the filters.

 

[KStatefan]

When they need it for the membrane and DI resin. Twice a year for the filters.

You might not have to ever replace your membrane with a tds that low going to it. I am 10x that and my membrane is 5 years old.

 

[mckinney0171]

A lot of places that sell filter media will tell you every three months replace it. I do every six months personally.

 

[pecan2phat]

Membrane was based on TDS reading after the membrane, basically if the rejection rate was significantly over the published rate of the incoming source water.
As for sediment and carbon, I use to change them out every 6~7 months when I did water changes. No that I've cut that down to maybe 3x per year, I change out these filters every 12 months since it's mainly utilized for top off and drinking water. Having said this though, I do this based on the known fact that my water utility does not add Chloramine.

 

[APC]

I follow the TDS - once it goes above 0, I replace. here in the suburbs of Atlanta that works out to about every 9 months or so, making about 50 gallons per week.

 

[Waters]

I have replacement filters on hand at all times, and change as soon as my TDS reads anything but 0.

 

[Oshengems]

I tested my tap water again last night I’m actually at 32, originally I just dipped the lil probe in a cup of water and got 46 I placed it in the inline just to double check and got a Lower reading, I ended up replacing the carbon,Di resing and the micro filter since I got them just to be on the safe side but now reading this feel I could’ve held of a month or 2

 

[ScooterV]

I'm lucky on source TDS as well, although just a little higher. My tap water is usually 45-50 TDS. I am at 2 post RO and 0 after DI. RO is a 150 gpd water saver so the rejection rate seems fine to me. I got it used, and no idea how much water had already been run through it and I put another year on it before changing the membranes "just because". I'm thinking I wont bother again unless post RO TDS rises. DI I have two and I rotate them only when I see TDS at 1.

I replace sediment and carbon more often though. It's in the garage, hotter, and gets light so when it starts to look green or nasty I replace them even though likely not fully utilized. Need to get some of those 1980's leg warmers and cover the canisters, lol.

 

[Oshengems]

I think you could sell your tap water. 1.5 years must be some kinda record.

lol

I actually was thinking that they sent me a faulty unit lol, I tested my hot water it was about 68 and cold 32 surprisingly low idk why I assumed my water was above the 100, I do know the NYC water does the best bagels let’s hope it does the same for my tank lol

 

[andrewkw]

You might want to consider replacing sediment just to increase efficiency, but given your source water it's very likely your filters are still good. You have slightly better water then me. Mine is about 50TDS and I generally get 1 year out of DI 6-8 months carbon 3-4 months sediment. I go by both the colour change DI and when tds reaches 1. This was a real shock to me as I heard so many horror stories about wells exhausting DI. I used to get just a couple of months out of DI on city water (175 TDS).

 

[chipmunkofdoom2]

The final TDS reading only tells you if your DI is depleted. It doesn't tell you anything about how the rest of the filters in your system are functioning.

The prefilters should be replaced every six months on a schedule, or when pressure drops and chlorine/chloramine starts showing up in your waste water. The reason for this is because they protect the RO membrane. Chlorine/chloramine are pretty hard on a TFC membrane. The RO membrane can last many years if properly protected, so doing so is worth the money.

The RO membrane needs to be replaced when it can no longer remove at least 96% of the solids from the water. To determine this, test the water's TDS after the membrane. Then, test your tap water TDS. Divide the post-membrane TDS by the tap TDS. if the number is greater than 0.04, it's time to replace the membrane.

The DI resin should be replaced any time that the final TDS reads above zero.

 

[Opus]

The sediment and carbon filters do nothing to tds, so you can't base replacement on that number. Their sole purpose is to protect the RO membrane. The sediment filter takes out the larger particles and the carbon takes out the chemicals that could harm the RO membrane. You have 2 options on deciding when to change the filters. The first is what most people do and setup a schedule. Most do it between 6 to 12 months depending on how much water you produce. The other option is to have pressure valves setup on your filters and change them when there is a significant drop in pressure from the filters getting clogged up. The RO membrane is based on your tds reading after the membrane. Most membranes should be getting 98% or higher rejection rate, with 95% being the minimum. It is up to you on what point to change out the membrane. Are you OK with 97%, if not then change it. I'm getting 99% on mine. I have a tds of around 450 from the tap and I'm getting 2 after the RO membrane. As for the DI resin, change it once it starts reading above zero. Don't rely on color changing. I've produced 0 TDS water for many months after the color changed on my DI.

Fyi, when changing the sediment and carbon filters, run 5 to 10 gallons thru them separately to get the particles out of them so they don't clog the next filter.

 

[Opus]

You might want to consider replacing sediment just to increase efficiency, but given your source water it's very likely your filters are still good. You have slightly better water then me. Mine is about 50TDS and I generally get 1 year out of DI 6-8 months carbon 3-4 months sediment. I go by both the colour change DI and when tds reaches 1. This was a real shock to me as I heard so many horror stories about wells exhausting DI. I used to get just a couple of months out of DI on city water (175 TDS).

You must use a lot of water or their is an issue. With 50 tds from the tap you should be getting less than 1 tds going to the DI. That would mean you should get around 4400 gallons of 0 tds water from a DI cartridge.

 

[andrewkw]

You must use a lot of water or their is an issue. With 50 tds from the tap you should be getting less than 1 tds going to the DI. That would mean you should get around 4400 gallons of 0 tds water from a DI cartridge.

Interesting. I guestimate about 2000 gallons a year. I actually think I changed the DI on January 1st just so I wouldn't forget about it. According to your numbers I could get 2 years from them. I've only lived in my house 2 years and the water quality is vastly different to what I was used to in the past.

 

[squampton]

My tap is very consistent 10-13 TDS.

I have had this unit running 2 years almost, I do change the carbon filter twice a year, but the sediment filter, haven't changed it yet, no drop in pressure, and when I took it out and looked at it, looks mostly brand new still, so I don't see a need to change that one until there is a drop in pressure.

I don't use DI, I get 0 on 2 different TDS meters one inline and one handheld, and no negative effects on the tank, and a lot of local reefers don't use DI, and some just use straight tap with prime.

 

[joqubr]

in New Orleans 250-300 TDS going in 0-2 TDS coming out -5 stage system i only make about 50 gal a month, changed DI once in 12 months changed mostly because it was not packed tight the first time