Aquaculture Systems Technologies, LLC (AST) was founded by Douglas Drennan, in October 1995, as a direct result of the acquisition of Armant Aquaculture, Inc. (AAI). AST acquired from AAI certain assets including, but not limited to, the exclusive manufacturing, marketing and sales rights for "Propeller-Washed Bead Filters" and similar non-exclusive rights for the "Bubble-Washed Bead Filters". Both filter configurations are patented, and AST has an exclusive licensing arrangement with the patent holder. Shortly after completing the acquisition, Douglas set about refining the complete line of propeller-washed bead filters which his new company would offer, doubling the number of filter models available from three units (PBF-8, PBF-20 and PBF-30) to six units (PBF-3, PBF-5, PBF-10, PBF-25, PBF-50 and PBF-100) and improving the design by increasing pressure tolerances from 15 psi to 20 psi on all of the fiberglass units, installing FRP coupling in place of bulkhead fitting for the inlet/sludge outlet on the side of the filters and using mechanical seals in place of packing on the filter head where the shaft penetrates the filter hull.

Today, AST's product line features ten propeller-washed bead filter models with bead capacities ranging from 3 ft3 to 100 ft3 and seven bubble-washed bead filter models with bead capacities from 1/4 ft3 to 10 ft3 . These filters are often referred to as bioclarifiers for their ability to perform both biological and mechanical filtration in a single unit. Bead filters operate very much like submerged rock beds or undergravel filters, with the added advantage of easy cleaning.