I was one of the many who silently suffered through the design flaws of the Klir DI-4. A little history... About 4 years ago, I decided to add a 50G cube aquarium for only RBTAs, rock flower nems, and a couple of clowns. With this build, I purchased an acrylic Fiji-20 Advanced Cube Reef Sump. After a year of trying different sock filters, filter fleece, and filter pads, I decided to upgrade to a Klir DI-4. Almost immediately, I noticed that I was cleaning more detritus in the downstream chambers of the sump than I did when I had the sock filters! On balance though, I stayed the course with the DI-4 because (1) I could find no other off-the-shelf product that wouldn't require a major sump mod and (2) I hated dealing with the mess of socks and on top of that, I was traveling often and needed a solution that wouldn't require my personal attention every 4-5 days.
As time passed, my frustration with the DI-4 grew. Why all of the escaping detritus?!? After a deep clean of the sump, I was able to get a clear picture of what was happening--IMHO, it's a design flaw in the DI-4. I researched forums and only found commiseration from other current and previous DI-4 owners. I tried tech support from CoralVue, but their bottom line response was that I was outside of the warranty period--no recommendation for a fix. So, in summary, here's the issue: there is zero tension holding the unused fleece roll, so only water pressure holds the fleece in place along the sidewalls of the device. The design flaw is that there is way too much space in the sidewalls. Before the water level in the DI-4 chamber rises high enough for the sensor to advance the fleece, water pressure will often push the fleece outward, opening a gap between the edge of the fleece and the sidewall, creating a stream (in many cases, streams) of unfiltered water that bypasses the fleece.
I tried several DIY fixes, the most promising of which was the addition of zip ties after the unused roll dispense point to create some tension in the fleece, but this was only marginally successful. Sometimes it worked and the fleece would advance, but sometimes it didn't, and when a bypass stream started, I was forced to press the fleece advance button on the controller and keep my fingers crossed for the next fleece advance... or not.
The solution finally became apparent after I installed a Red Sea ReefMat 1200 in my 200G aquarium. I needed to have some 3-D printed wedges with smaller holes to insert in the large gap spaces of the DI-4 sidewalls. Voila! It worked like a charm! I'm back in love with the DI-4!!! My son printed these wedges for me. You can see them on his Instagram at
As time passed, my frustration with the DI-4 grew. Why all of the escaping detritus?!? After a deep clean of the sump, I was able to get a clear picture of what was happening--IMHO, it's a design flaw in the DI-4. I researched forums and only found commiseration from other current and previous DI-4 owners. I tried tech support from CoralVue, but their bottom line response was that I was outside of the warranty period--no recommendation for a fix. So, in summary, here's the issue: there is zero tension holding the unused fleece roll, so only water pressure holds the fleece in place along the sidewalls of the device. The design flaw is that there is way too much space in the sidewalls. Before the water level in the DI-4 chamber rises high enough for the sensor to advance the fleece, water pressure will often push the fleece outward, opening a gap between the edge of the fleece and the sidewall, creating a stream (in many cases, streams) of unfiltered water that bypasses the fleece.
I tried several DIY fixes, the most promising of which was the addition of zip ties after the unused roll dispense point to create some tension in the fleece, but this was only marginally successful. Sometimes it worked and the fleece would advance, but sometimes it didn't, and when a bypass stream started, I was forced to press the fleece advance button on the controller and keep my fingers crossed for the next fleece advance... or not.
The solution finally became apparent after I installed a Red Sea ReefMat 1200 in my 200G aquarium. I needed to have some 3-D printed wedges with smaller holes to insert in the large gap spaces of the DI-4 sidewalls. Voila! It worked like a charm! I'm back in love with the DI-4!!! My son printed these wedges for me. You can see them on his Instagram at
