Fluval Canister Filters:
Continuing our discussion of canister filters (view Part 1 and Part 2), we come to the Fluval family of canisters. The most popular series is their Fluval ’06 series of multiple stage filtration. As with most types, the canisters come with a shut-off valve disconnect to remove the hosing during cleaning. The motorhead uses two large, lock down clamps, and the seal ring sits recessed in a groove around the bottom of the motorhead. To facilitate the restart, the canisters also have a self-priming assembly. The Fluval series takes a different approach to the layering of the three types of media. Their design places the mechanical foam cartridges vertically along one side of the canister, outside of the stack of media baskets for the chemical and biological media. This provides more initial contact surface area for the mechanical foam and also makes it possible to open up the canister and just remove/clean the mechanical filter, leaving the media baskets in place. The Fluval canisters have 2 to 4 media baskets and recommend you fill the bottom chamber(s) with chemical media (they come with Activated Carbon) and the upper chambers with bio-media (Bio-Max Ceramic Rings). As with all canister filters, the chemical media will need to be replaced every 2-4 months while the bio-media simply needs to be tumble cleaned in water from the aquarium. The mechanical foam cartridges are usually good for several squeeze cleanings before they would need replacing.
For larger size aquariums, Fluval offers the FX6 canister filter. This canister has one of the higher rated flow rates of 925 GPH, though loaded with media, the circulation flow rate is 625 GPH. The Fluval FX6 takes a somewhat industrial approach to the type and quantity of media inside the canister. There are three large media baskets stacked on top of each other, with two foam mechanical filters wrapped around the circumference end-to-end, for a total of six foam pads. This provides a massive surface area for the initial mechanical filtration. While you can place just about any type of media you like in the media baskets, the unit initially comes with two Bio-Foam pads in the top chamber, Bio-Max Ceramic Rings in the middle, and a carbon fiber pad on the bottom, with room for two media bags (included) of your choice of media. Hagen also makes Fine Filter Pads and Water Polishing Pads that can be placed in the media baskets. Many hobbyists like to use the Polishing pad on the very bottom to protect the impeller of the motor. One unique feature to the FX6 is the placement of the motor as an external unit, attached at the bottom of the canister filter. The pump also uses Smart-Pump Technology with a built in circuit board to monitor the pump and periodically shut down the pump to allow the canister to purge any air trapped inside, then starts back up immediately. Given the 5.9 liters of internal volume, the FX6 has a drain valve to allow you to drain off the water before picking up the unit for maintenance. The media pads can be used several times before replacing. The FX6 filter also comes with two dials on top of the motorhead where you can set the date of the last water change and the last filter maintenance to help you monitor your cleaning schedule. Now, if they could just automate the actual cleaning itself!
The last line of canisters offered from Hagen is the Fluval G Canister Filter series. These have an appearance different from all other canisters on the market. They have a sleek, modern cube design with a glossy black and silver finish. If you did not see the intake/return hoses, you would probably not think of this item as a filter. In the next step of user friendliness, the G Series is designed so you can remove the Pre-Filter Mechanical Cartridge and the Chemical Cartridge without shutting down the canister. The Pre-Filter is offered as a standard no by-pass pleated cartridge, or as a Fine Pre-Filter capable of filtering particles down to 75 microns or larger. You would need to have two sets of the cartridges so you can quickly replace the one being removed for cleaning or refilling. Also inside are large trays of the Fluval G Ceramic Nodes for biological filtration. Fluval recommends replacing about one-half of the Nodes every 6 months. Built into the face of the canister is a monitor that displays the readings from the Hydro Tech system. This program will display the time from the last changing of the mechanical and chemical cartridges, the actual water flow rate, and the temperature and conductivity of the water. It has an alarm that displays if the flow is too slow, and you can program a “set point” for the temperature and it will alert you if the actual temperature varies too much. Please note that the G Series canister does not regulate a heater, just reports the temperature.