The Tunze Stream family of in-tank powerhead circulation devices is divided in three, the Nanostream, the Stream 2 and the Masterstream.
The pumps are grouped according to physical size and pumping capacity. All pumps within the same category have similar physical dimensions, but offer a range of flow rates and controllability.
Nanostream pumps have physical dimensions very close to that of a racquetball, or slightly smaller than a tennis ball. The outside diameter of the spherical pump is 2.7 inches and the diameter of the directional outlet is slightly over 1.5 inches. The Nanostreams range in flow rates, starting with the 6015′s 475GPH going up to the 6095′s 2,500GPH. Three of the Nanostreams are non-controllable (the 6015, 6025 and 6045) and two are fully controllable DC pumps (6055 and 6095).
At 3.5 inches the Stream 2 powerheads have a pump diameter slightly smaller than a softball. They have outlet diameters that range from two to three inches. Their flow rates start at the bottom with the 6065′s 1,700GPH and go up to the 6255′s immense and wide-flowing 4,800GPH. The 6065, 6086 and 6125 are steady stream pumps while the 6105, 6155 and 6255 are fully controllable DC pumps.
At the top of the Stream family tree is the Masterstream triumvirate. Suited for aquariums ranging in size from 800 gallons to national, these three will be for most admired from a distance. All three Masterstream pumps are fully controllable and the series ranges from 5,200GPH up to 39,500GPH.