Bulk Reef Supply

Bulk Deionization Resin (Color Changing)

Grouped product items
One Cartridge Refill (1.25 lbs.) DI Resin (Color Changing)

SKU: 200123

In stock

$10.49 $14.99

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1.5 gallons (7.5 lbs.) DI Resin Color Changing

SKU: 200121

In stock

$45.84 $65.49

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Why does BRS recommend this?

We recommend color changing resin for the fact that it will physically change colors as it gets exhausted.  That allows you to monitor the consumption of the DI resin and know when to change it out.  If you have a TDS meter we still recommend color changing resin as it will let you know when to monitor your TDS meter for when TDS starts creeping through the DI resin.  When it comes to packaging not just any packaging will do, we package our DI resin in sealed Mylar bags for ultimate effectiveness and shelf life.

DI Resin is necessary to reduce Total Dissolved Solids (TDS) to zero and is the last stage of an RO/DI unit. Resin is sold in economical bulk bags as well as single use pouches. The resin is designed to be used with one of our refillable DI cartridges. This refillable design saves a small fortune over proprietary sealed cartridges.


Color Changing Mixed Bed DI Resin

  • Changes Color from Blue to Brown as the media is exhausted.
  • 1.5 Gallon - Fills 6 standard 10" refillable cartridges
  • 1.25 lbs. - Fills 1 standard 10" refillable cartridge
  • Packed in foil-lined 4mm Mylar bags to preserve quality (see Full Details for more info)
  • 2 year shelf life (unopened)


BulkReefSupply.com takes pride in the proper packing of our DI Resin. DI resin begins depleting when exposed to air. To avoid this, we package all of our DI resin in foil-lined 4mm Mylar bags to prevent exposure to air that may deplete the resin while its waiting to be used. Our resin can remain packaged this way for 2 years without losing its capacity. Our bulk DI bags are perfect for reefers who process a lot of water or otherwise go through resin quickly. The bags are resealable via a featured zipper lock. Keep in mind this won't be as good as the original seal so we recommend them only for reefers who need a high volume of DI Resin. Otherwise, purchase the single refill packs for optimal freshness up to two years.


To get maximum life from your DI resin please takes the following steps


  • Ensure optimal operation of your RO membrane. The higher your membranes rejection rate the fewer TDS your product water will contain resulting in longer lasting resin. The best way to keep the membrane rejection rate up is to monitor and change your prefilters appropriately as well as maintain at least 50psi going into the membrane.
  • Ensure the resin is packed in the cartridge securely. The resin should be packed very tightly. When squeezed, there should be almost no flex to the cartridge.
  • The initial couple minutes of water from your RO membrane will always be high, this is commonly referred to as TDS creep. Diverting the first few minutes of water down the drain can often greatly reduce DI resin consumption.
  • Maintain low levels of carbon dioxide in your water supply.  Excess carbon dioxide will deplete DI resin quickly. If you are depleting resin quickly and have already :addressed the two options above, excess carbon dioxide is the likely culprit. You have two choices:
    • Collect the water coming from your RO system in a large container, add a powerhead or airstone and allow the CO2 to gas off. Then pump the water through your DI resin.
    • Skip all that mess and just buy resin in bulk.


    DI Cartridge Refill Instructions

More Information
Resin Type Color Changing
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Product Questions

How long will this last once opened?
Question by: Ted Schneider on Dec 11, 2023, 2:33 PM
Unfortunately DI resin begins depleting when exposed to air, so it is not recommended to use if the bag has been opened for an extended period of time.
Answer by: Laura (BRS Staff) on Feb 7, 2024, 10:24 AM
Are these suitable for drinking water or do they, as one reviewer mentioned, impart a taste on the water? It's more convenient for me to add the DI stage after the tank on my main RO system so I don't have to mess with T connections and slow DI output.

Would the premium DI resin be more suitable for this application?
Question by: Jason on Feb 3, 2023, 3:55 PM
We do not advise drinking dionized water. It will certainly impart a taste on the water and many people believe it is unhealthy due to the complete lack of minerals. We definitely advise running a tee off your line if you plan to drink the water.
Answer by: William Reed (BRS Staff) on Feb 17, 2023, 10:15 AM
Thanks for reaching out! We do not recommend that you drink De-ionized water as it provides no health benefits to you. We recommend just drinking reversed osmosis
Answer by: James Johnson (BRS Staff) on Feb 17, 2023, 11:33 AM
Does this Di resin remove silicate?
Question by: Johnny Mejia on Apr 7, 2022, 8:13 PM
Hey there,
Thank you for reaching out to us. Yes, this will remove small amounts of silicates. Running anion and then a mixed bed, will be a better option though.

Please let me know if you need anything further and take care!
Answer by: Matt Lucero (BRS Staff) on Apr 8, 2022, 7:40 AM
I still have a fair amount of this resin left, but I would like to switch to your 3 canister system with the cation, anion, and then mixed bed in the last. Is this mixed bed the cation or anion mixed bed? I'm just wondering so I can use it up first before buying the new pro mixed bed resin. Thanks.
Question by: Paul on Jan 24, 2018, 2:07 PM
The final stage can actually be either mixed resin. It will ultimately depend on which single bed runs out first. Since everyone's source water is different it is hard to say which will go first, but you could start with the mixed bed resin you have and just make sure to keep an eye on the color changes of the single bed.
If your anion single bed runs out first, then you would want anion mixed bed resin since that would be more likely to break through, and if your cation single bed runs out first, then you would want to use the cation mixed bed resin.
Answer by: Charlie on Jan 25, 2018, 5:08 PM
What ratio of cation/anion resins is used in the mixed bed?
Question by: Ollie on Jan 5, 2018, 5:52 PM
Thanks for contacting BRS!
The ratio of our mixed bed DI resin is 50/50. Have a great day!
Answer by: Josh Cuta on Jan 11, 2018, 12:37 PM
BRS, I recently watched your video on DI resin - Great Video!!! I currently run a dual staged mixed DI bed. How can I tell if I would benefit from running a straight anion and/or cation prior to the mixed bed?
Question by: Christopher on Nov 3, 2017, 12:20 PM
Hi Christopher, great question!
The main reason for running non-mixed bed resins is that in most cases you are wasting some portion of the cation or anion resin in a mixed bed when you change your cartridge. Since every water source is going to be different its hard to say which one that is in your case.
Running single bed resins allow you to change out the cartridge only when it is completely exhausted.
Running the 3 stage system we recommend is going to give you the best possible water and ensure you aren't wasting resin. That being said, if you would like to stick with a dual DI system mixed bed resin is still going to give you great results.
I hope this helps!
Answer by: Nick on Nov 25, 2017, 12:52 PM
One of my resin filters looks solid grey from the top down (the bottom inch or so looking normal). Although I changed the resin filter not long ago, I changed it out again today. Packed it with new resin from a new, unopened foil pack, and as soon as the water filled the canister it turned that grey color again. I have to assume it must be air bubbles, but but it's so solid looking. there must be an air bubble enclosing each granule of resin to produce this effect. Honestly it looks like concrete. Any idea? I've never had this happen before.
Question by: Meg on May 28, 2017, 4:50 PM
The grey appearance is likely the result of air on the inside surface of the cartridge, as you guessed. It would be nearly impossible for the media to actually be exhausted that quickly, and even if it were, it would change to a brown/orange color, rather than grey. I would ensure that your media is tightly packed to avoid the possibility of channeling in the media, and you may also want to give the unit some time to run as much of the air will likely get purged after a while and once the media is fully wetted it would darken in appearance.

Hope this helps!
Answer by: Zack on Jun 5, 2017, 4:55 PM
What are the 'beads' for the DI made of? Is this something that can be thrown away in the trash after it has been depleted? Are they plastic based - such as microbeads that will break down into smaller and smaller pieces?
Question by: Aron on Dec 4, 2016, 2:39 PM
Hey there,
While there are a few different resins available, most DI resins will be made of a porous polymer called polystyrene sulfonate. There is nothing toxic about the media itself and should be fine to dispose of in your regular trash. Have a great day!
Answer by: Zack on Dec 21, 2016, 1:45 PM
How long will the DI resin last in a non opened vacuum sealed bag?
Question by: Kevin Schulze on Apr 14, 2016, 5:47 PM
Great question!
Di resin can last in vacuumed sealed bag around 6 months. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 19, 2016, 12:13 PM
Does this Di resin remove silicate?
Question by: Louie Pistorino on Apr 4, 2016, 7:56 PM
Recently purchased a number of small individual vacuum sealed pouches. Is it better to store them in a fridge or freezer for prolonged life, or will room temp be more sufficient?
Question by: Travis on Jul 31, 2014, 12:22 PM
Hi Travis,
The main enemy of DI resin is exposure to co2, which is why we use the Mylar foil lined bags and then vacuum seal them. Just store the bags in a room temperature place and you will be just fine :)
Answer by: Bulk Reef Supply on Jul 31, 2014, 12:22 PM
Will your RO/DI filters fit my Coralife II
Question by: Alan Cox on Feb 8, 2014, 4:03 AM
HI Alan,
They sure will. All of the above (and basically any RO/DI unit) uses standard 10" cartridge sizes.
Answer by: Bulk Reef Supply on Feb 8, 2014, 4:03 AM
Ok, I'm using a color change di resin now, not BRS, but same principle. I'm kinda new to ro/di making. The bottom of my cannister has a light brown color too it now that goes up about 2 inches. TDS is still at 0. Do you change it when just a little brown going up or wait till whole cannister has turned brown? Sorry to be so naive but like I said not been doing this long. Thanks for any suggestions you may have.
Question by: Valerie on Jan 29, 2014, 7:51 AM
Hi Valerie,
You want to wait until the TDS starts to read above 0 as the TDS meter is the ultimate say, but generally speaking that is going to correspond with the DI resin turning almost entirely brown.
Answer by: Bulk Reef Supply on Jan 29, 2014, 7:51 AM
I noticed that your DI resin is vacuum sealed. If I purchase the larger bag that has 6 changes in it, once I open the bag, it will no longer be vacuum sealed. Will this affect the product in any way?
Question by: Earl on Jan 4, 2014, 11:12 PM
Hi Earl,
If you use the resin quickly it wouldn't have any sort of noticeable effect if you close the seal after each use but if you are purchasing and planning it for long term storage then you would be better off purchasing the individual bags.
Answer by: Bulk Reef Supply on Jan 4, 2014, 11:12 PM
di resin straight out of a brand new bag already has 40-50% brown in it.. is it already exsausted??
Question by: john on Dec 22, 2013, 6:42 AM
Hi John,
No it is not. Half of the DI resin beads are always brown and half are blue. The brown always stay brown and the blue resin changes from blue to clear as it is exhausted giving the appearance that the entire cartridge has turned brown.
Answer by: Bulk Reef Supply on Dec 22, 2013, 6:42 AM
Does the color changing di turn noticeable brown? My di has brown in it however you really have to look close to see it.
Question by: Andrew on Sep 6, 2013, 10:38 AM
Hey Andrew,
The DI resin changes from a dark blue/black color to a light gold yellow color. You should easily be able to tell from across the room!
Answer by: Bulk Reef Supply on Sep 6, 2013, 10:38 AM