Top Reverse Osmosis DI Resin Mistakes to Avoid

Categories: Reverse Osmosis, Saltwater

Last updated: Jan 29, 2025

The last and final stage of your RO/DI system is the DI stage where water passes through deionization resin. DI resin is a special material that captures dissolved ions from the water. It is incredibly effective at removing pesky impurities that might pass through the previous filter stages of your RO/DI system, protecting your tank from dangerous compounds like ammonia, phosphate, and silicate. When it comes to RO/DI system maintenance, DI resin is usually the most costly filter material that needs regular replacement. If exposed to elevated levels of impurities, DI resin can exhaust very quickly. Staying on top of RO filter replacements is not only important for the health of your tank, but your wallet as well.

Don't Make These Mistakes When Refilling Your DI Cartridge!

Replace your Color-Changing DI resin when the color change is about 1" from being completely exhausted. If you wait until all of the media has changed color, you will be allowing impurities to pass through the filter and eventually get into your aquarium.

2. Keep loose DI resin contained during maintenance

Loose DI resin is messy and gets everywhere. It sticks to surfaces via static, it's spherical and rolls around. The point is, it's hard to clean up. Consider using a plastic tote, cardboard box, or even a trash can when replacing DI resin media to avoid spillage. Pour the exhausted resin into the trash bin and refill it with new media over top of a container. Trust us when we say, you will spill some resin and having it contained inside of a box or container will save you some real headaches when cleaning up.

3. Always use proper personal protection equipment during maintenance

Gloves and eye protection are highly recommended when working with loose DI resin. Similar to our reasoning for the previous advice, the resin sticks to everything and is tiny. It can get in your eyes, which doesn't feel great and is difficult to remove, and it's even harder to clean up. Some eye protection and gloves should save you from experiencing these setbacks.

4. Always tightly pack DI resin inside the filter cartridge.

If DI resin is not packed down into the cartridge sufficiently, the water will create channels as it upflows through the media. This results in poor media performance and you won't be able to get the full use out of your DI resin. The water should evenly distribute and flow upwards through the entirety of the media.

Read More: How To Change Your RO/DI Filters

5. Use a new DI resin filter sponge every time you swap the media

The sponges inside your DI resin cartridge will lose their form and become smashed down. It's important these sponges stay intact for optimal performance and to keep the DI resin contained inside the canister. We recommend that you replace the sponges with every exchange of resin media.

6. Consider using the pre-packed DI resin cartridges to save yourself the hassle!

If you want to simply save yourself from hassling with loose DI resin altogether, consider the pre-packed DI cartridges. While you will end up spending a few extra dollars on your filter replacements, the ease of installation is reason enough for many hobbyists to opt for this route.