SHOWER FILTER

This past year (2005), I presented information at the Atlanta Koi Show regarding my high flow rate shower filter. The newest design is a combination shower filter that not only is a biological filter but a sediment separation filter as well. Here is how it works. I have a stack of five (5) crates, the top four filled with lava rock. These top crates act as they would in a traditional shower and are purely used for biological filtration. The shower sits in a tank and is gravity fed back to the pond. The system is pump fed from the power skimmers and delivers about 6500 GPH to the shower. The lower, 5th crate, is fully submerged in the tank and filled with K1 type media. I used my close-sided plastic crates for this application. The key to this design is that the gravity outlet back to the pond is installed as high up as possible in the tank. I sort of create a reverse weir where the incoming water (from the crates) is lower then the outlet return to the pond. The result is that sediments are forced downward (by the violent action of the shower) into the tank where they settle. The contributing factor to success is that the return line to the pond is much higher then the water level at the bottom of the submerged crate. I installed a 2” ball valve at the bottom of the cone bottom tank that the crates sit in for traditional tank flushes. 

The first two pictures show the frame assembly with tank. As you can see, the return back to the pond is much higher then the bottom level of the lowest crate. Also note that the support for the lava rock filled crates is integrated into the tank frame. It supports the weight and not the tank.

The next two pictures are close-ups of the custom splash skirts that I used to keep the water contained within the tank. Even though I used closed sided crates, the splash would be great enough to make a real mess. I used a special EPDM epoxy to bond a stainless bar on either end of the skirts. Integrated some stainless “S” hooks in the design and now it’s real easy to remove the splash skirts. I intentionally make the skirts too short so they are stretched ever so slightly to keep them in place.

This next picture is the system in operation. It is currently set-up in the garage and is used as a quarantine system. This coming spring, it will be installed in the main pond.

This picture is of my existing set-up that has been running for over two seasons. I plan to reduce the current footprint, integrate the cone bottom tank and splash shields with this new design. The future plan is to install a high end motorized ball valve to replace the manual dump valve and automate this filter. I have enough spare I/O in my automated Sodium Thiosulfate dosing system to not only provide the automated controls but also top the pond off automatically after a tank drain.

This final picture shows only a day or so of solid separation from my current set-up. I do have a ball valve that I use to drain the tank but the flat bottom tank used in this initial prototype causes grief to get it real clean.

The key to this project is the crate design and how well water flows through it. Air gaps between the media aids in the overall efficiency of the filter as well. The crates stack one on top of the other and nest with interlocking tabs to make a sturdy tower. The following picture shows the bottom of the crate. This design was established for a full flow through effect. Experimentation at several ponds in the south east utilizing this technology is currently underway. Stay tuned for more exciting news on this inexpensive shower.