Some folks are enamored by what is called a “bead” filter (Aquadyne) or, euphemistically, a “high performance filter” (got to love the marketing folks). It is NOT a bead filter, it doesn’t use beads! And it is not a “high performance filter”. This filter is about $1,100 (i.e. incredibly expensive) for what is a K1-type stationary submerged bed about the same size as a much cheaper 40-gallon DIY fluidized bed sump ($150). And the sump will be much more efficient!
These filtration units look very suspiciously like just $300 sand filters for pools which have had a new label put on them. Hhhhmmm…………..
The manufacturer claims to have a “patented” K1-type extruded plastic media design that doesn’t channel or clog. The patent and its claims are simply fiction. In the 1980’s patent law in the US was changed to allow the patenting of items that simply don’t work the way the claims of the patent are written.
The benefit-to-cost ratio for these filters is extremely poor. Nexus is a similar very high-priced filter that uses K1 media.
Rachel O’Leary came up with the idea of taking a pool sand filter, removing the sand, and filling it with K1 media. Attach an external aquarium pump. This would do the same thing as these bead filters only at a much lower cost. Note that K1 is an excellent stationary filter media as shown by testing. K1 does not have to be fluidized to work well.
Source: Aquariumscience.org – David Bogert