We have been posting about the two different types of filtration in our new Grow-out Greenhouse.  Today’s post will explain our Polygeyser setup.  For this particular filtration system, we bought an off the shelf filter with no pre-filtration.  However, instead of using the suction pressure it is gravity fed.  According to the manual, we can feed up to 10lbs of food per day per system.  While this is a smaller footprint than the vortex system, the price tag is higher at about $3800.  The big advantage to this system is that it automatically backwashes using a small amount of air.    Both the vortex system and the Polygeyser are both air driven to dump dirt and water.  They are both set to do this automatically six times a day.  This is how we attempted to level the playing field between the two different systems.

In an earlier post, we showed the copper tubing running underground from our new Grow-out Greenhouse to our Nisai Greenhouse.  We have just finished the installation of the new heat exchanger in the Nisai Greenhouse.  Whereas the heat exchangers in the new Grow-out Greenhouse are external to the water, this heat exchanger is set inside the filter pit.  It is a series of coils that are filled with the warmed water, which heats the surrounding pond water.  We installed it in the filter pit instead of the actual tank just so that the koi would not injure themselves if they brushed up against.  The system we are heating contain our BETN koi and our 555 koi.

As promised, we’d like to share some details about the different filtration systems we are using in our Grow-out Greenhouse.  This greenhouse is designed for the growing of our small high-quality koi.  These koi were chosen during their harvest this fall.  There are 12, 10’ diameter fiberglass tanks, approximately 1800 gallons each.  Every set of two tanks has its own filtration.  Three sets of two tanks are using our new vortex system and the other three sets of tanks are using Polygeysers.  Today’s post will go into more details about the vortex system.

 For the filtration, we utilized two vortexes for each system.  One is setup as a true gravity fed vortex for settlement (mechanical filtration).  We have branched off the waste line to an airlift so that we can do periodic automated dumps of the accumulated solids.  This will allow us to do set water changes per day.  The other one has been adapted for a central aeration source to mobilize K1 (moving bed, media).  This design resulted in a very small amount of air to drive 13 cubic feet of K1.   We have learned that a cylinder shape uses the least amount of air to mobilize K1.  Lastly, with the 13 cubic feet of K1, we should be able to feed 4lbs of food per day per system. 

 To summarize, the vortex system allowed us to purchase an off the shelf stand filter and retrofit it to use K1.  This was advantageous due to its low cost of approximately $2000.  The disadvantage is that it takes up a larger footprint.  For your pond setup, space is something important to consider.

 Keep an eye out for the post that details our Polygeyser setup…