Reef Pure Mixed Bed Colour Indicating DI Resin
Water type
Freshwater + Marine
Fits
Standard refillable DI / mixed-bed cartridges
Reef Pure Mixed Bed Colour Indicating DI Resin
Polishes RO water to a true 0 TDS, and tells you when it's spent. Reef Pure Mixed Bed Colour Indicating DI Resin is a nuclear-grade mixed-bed resin — cation and anion beads in one fill — that finishes off reverse osmosis water to better than 10 megohm resistivity and a zero TDS reading. It's sold as a loose refill for standard DI cartridges, in a small 540 g pouch and a larger bulk pack, and it changes colour from blue to a light brown/gold as it exhausts.
Key features
- True mixed-bed resin — cation and anion resins combined, polishing RO permeate to 0 TDS / >10 megohm resistivity.
- Colour-indicating — the bed visibly shifts from blue to light brown/gold as capacity is used up, so replacement isn't guesswork.
- Two pack sizes — a 540 g pouch for a single refill, and a larger bulk pack for anyone refilling regularly.
- Foil-lined mylar packaging — keeps the resin sealed from air until you open it, since exposure shortens shelf life before it's even installed.
Specifications
| Brand | Reef Pure RO |
|---|---|
| Type | Mixed-bed, colour-indicating DI resin |
| Output quality | >10 megohm resistivity, 0 TDS |
| Packaging | Foil-lined mylar pouch |
| Suitability | Refillable DI/mixed-bed cartridges, freshwater or marine RO/DI systems |
Which size do I need?
| Pack | SKU | Net weight | Price |
|---|---|---|---|
| 540 gram | AA1577 | 0.62 kg | $29.95 |
| Bulk refill | AA0565 | Manufacturer figures are inconsistent — see note below | $149.95 |
Reef Pure's own listings for the larger pack are inconsistent — the product title reads "3.5 kg" while the stated net weight is 3.9 kg, against the 3.75 kg this SKU is listed at here. We can't reconcile that discrepancy from published sources, so we're not printing a single precise weight figure for the bulk pack until it's confirmed against the actual fill weight.
Cost per litre
Reef Pure doesn't publish a treated-litres figure for this resin, and DI resin capacity genuinely depends on the TDS and hardness of the RO water feeding it rather than a fixed number — so we can't calculate a reliable cost per litre for either pack size. If you know your feed water's TDS, your RO membrane supplier or a water-treatment reference can give you a working capacity estimate.
Suitable for, and not suitable for
- Suitable for: the DI stage of an RO/DI unit, in freshwater or marine setups, wherever a refillable cartridge is used.
- Not suitable for: sealed, non-refillable proprietary DI cartridges that aren't designed to be opened and refilled.
Care and maintenance
Replace when the resin bed has turned from blue to light brown/gold. Keep unopened pouches sealed until use — the foil lining is there to stop the resin degrading in storage.
Goes well with
A Reef Pure Reverse Osmosis Membrane upstream, since DI resin only polishes water that's already been through RO.
Warranty and delivery
As a consumable resin fill, this isn't covered by a fixed-term warranty; Australian Consumer Law protections apply regardless. Standard shipping for both pack sizes.
Common questions
Do I need this if I already have an RO membrane?
DI resin is a separate, final polishing stage after RO — it removes the small amount of TDS an RO membrane lets through, taking the water to a true 0 TDS reading.
How do I know when to replace it?
Watch the colour: fresh resin is blue and shifts to light brown/gold as it's exhausted.
How many litres will one pack treat?
Reef Pure doesn't publish a fixed litres-treated figure, because capacity depends on your feed water's TDS and hardness rather than a constant rate.
Can I use this in any DI cartridge?
It's designed for refillable/reusable DI cartridges. Sealed, non-refillable proprietary cartridges can't be opened to accept loose resin.
