In traditional ranchu keeping there are no conventional filters used, besides algae growth and an air-stone. Absence of filter requires 100% water changes every 4-7 days. Most importantly, it requires you being available to do the water change every 4-7 days. Pretty tough commitment for a traveling enthusiast like me.
So, I had to have a back up and designed a filter for mechanical and biological filtration to control ammonia and nitrites levels. A stand alone sump tank housing various mechanical and biological filter media would perform this role. After many consultations with the folks on a couple of forums, I have come up with the final design. I loaded the chambers with Eheim Substrate Pro Bio Medium and Seachem Laboratories Matrix Medium for biological filtration. For biological/mechanical filtration I used Matala Filter Media mats, two more finer filter pads and to "polish" the water - filter-floss.
|Sump Tank, Side View|
The water is pumped from the pond into the sump tank and then let flow back to the pond through the media by the gravity. I also placed two large air-stones in the pond hooked up to an air pump.
|Entire System Set Up, Top View|
The pond was set up in my apartment and had to look esthetically pleasing with most wires and hoses being hidden away. So, I designed and built the inclosure, trying to complement the fish in the most humble way. My goal was to achieve a good balance between functionality and esthetics. I even used plants around the pond commonly called "cast-iron plant" Aspidistra elatior from Japan. Ironically, its leaves were traditionally used for preparation of sushi battera style. Shh, I will never reveal this to my ranchu.
|Almost Finished Pond Set Up|
I wanted to have a water feature to complement the installation and came up with an idea of a bamboo aqueduct. I used a second "miniature" pump to pump small amount of water from the sump tank into the bamboo "pipe". The water runs through a couple of bamboo pipes, creating a beautiful trickling sound and gets aerated before porting back to the pond.