Fluval Multi-Stage 05 Series Filters

Written by Kmuda. Posted in Canister Filters






Powerful aquarium canister filter redesigned with added conveniences

  • Larger filter media capacity for improved aquarium water quality 
  • Aquarium canister filter includes necessary media for three-stage filtration

This aquarium canister filter adds extra conveniences to the powerful and flexible Fluval filtration line. Each Fluval Multi-Stage 05 Series Filter adds even more user-friendly features to ensure aquarium filtration is even easier to set up, customize, and maintain. Plus, each filter holds 35-50% more volume than round canisters of similar size and directs filtration through a complex flow path to maximize contact with the filtration media. Features patented Aqua-Stop Valve, multiple filtration baskets, and rim connector assemblies to keep the intake and output hoses in place on your aquarium. Multiple filtration baskets are already packed with the necessary media for mechanical, chemical, and biological filtration. Four distinct sizes - each with increasing flow rates and filter capacities - to suit any small to mid-sized home or commercial aquarium.

Each Fluval Multi-Stage 05 Series Filter minimizes filtration worries with a series of convenient features. Aqua-Stop Valve permits hose disconnects and easy-open, one-motion lock clamps makes routine cleaning and maintenance easy. Added to the ability to customize filtration with multiple, removable media baskets and adjustable flow rates, and you've got a canister filter that is convenient, efficient, and powerful.

Includes: Instant-prime system; single-motion lift-lock clamps; clog-proof intake strainer; dual-layer foam screen; and instructional DVD to ease set-up and use.

Features Fluval 105 Fluval 205 Fluval 305 Fluval 405
Pump Power 9 watts 9 watts 15 watts 21 watts
Flow Rate (max) 125 gph 180 gph 260 gph 340 gph
# Baskets 2 3 3 (divided) 4 (divided)
Filter Capacity 3.2 L (3/4 gal) 4.6 L (1-1/4 gal) 6.94 L (1-3/4 gal) 8.94 L (2-1/4 gal)
Filter Media Foam Sponge
Foam Sponge
Carbon (x2)
BioMAX (x2)
Foam Sponge
Carbon (x3)
BioMAX (x3)
Foam Sponge
Carbon (x4)
BioMAX (x4)
Aquarium Size up to 25 gallons up to 40 gallons up to 70 gallons up to 100 gallons









Total 3 Stage Filtration

  1. Mechanical - combines two thick layers of foam blocks with a clog-proof intake strainer to remove large dirt and debris particles. This design prevents the clogging of biological and chemical media - an important filtration step, since these types of media are most effective when unhindered by objects that minimize their contact with water.

  2. Chemical - included carbon may be substituted with a chosen chemical media to customize filtration for your specific tank. Chemical medias remove dyes, medications, and soluble wastes that pass through the mechanical filtration process, in addition to changing the chemical composition of tank water that is ripe with abnormally high levels of chemical toxins and/or pollutants.

  3. Biological - dedicated biological media fosters the growth of beneficial bacteria, which helps eliminate toxic ammonia and nitrite that accumulate in aquarium water. This bacteria culture biologically changes the ammonia and nitrite into nitrate, which is then removed with either monthly partial water changes or dissolved by natural plant and animal activity.

Safety and Easy Upkeep:

  1. Aqua-Stop Valve - convenient valve holds both the intake and outlet valves and creates an air and watertight seal that allows you to disconnect the hosing without breaking the vacuum. This allows you to open the filter cover for routine maintenance and cleaning and then start the system again without priming. This valve also allows you to regulate the flow of water through the filter system.

  2. Instant-Prime System - start your filtration system with a few, simple pumps of the easy-access priming pump, which initiates water flow through the check ball that is incorporated in the intake strainer.

  3. Lift-lock Clamps - durable plastic clips open the filter with a single-motion for cleaning and maintenance. This keeps the filter properly functioning during normal use, while also preventing the Pump Head from becoming dislodged from the canister by accidental bumps or curious fingers. Thus, your aquarium water remains within the closed filter system and off of your floor.

  4. Click-on Rim Connector Assemblies - minimize set-up time and hold the important intake and output lines in place within your tank with these simple, snap-together connectors. Designed to slip over the edge of your aquarium and secure all filter hoses to either the back or side tank walls.

Downloadable Fluval Multi-Stage 05 Series Filter Instructions PDF.
(Requires Adobe Acrobat Reader 4.0 or later - get it here for free)

Fluval Multistage O5 Series Review:

By Kmuda


The Fluval Multistage 05 series is a continuation of a line of filters that has been around for many years. My personal view of these filters is they are overpriced, over designed, poorly designed, with limited media capacity (when compared with rival filters), and are not dependable, suffering from the inevitable "Fluval Restart" issues. My Fluval is currently sitting in a closet, unusable.

The "Fluval Restart" problem is an issue that arises in this line of filters whereas they will not properly re-prime following maintenance, forcing you, as the aquarist, to struggle through the attempted restart, pumping the priming button, shaking the filter, whatever, trying to get water to flow again. The issue starts out small, where it does not take too much to get the water flow restarted, then increases in difficulty over time. My filter made it three years before it completely failed, but the restart problems started within 3 months of purchase. For every Fluval that has been in extended use, there is another that has failed because of this problem.

I can be quoted as saying, this line of Fluval filters are designed by Satan and manufactured in the depths of hades for the express purpose of making lives miserable. There are much better (and less expensive) options available.


  • At 450gph, the flow rate is above respectable.
  • The split design of the trays allows for increased flexibility of the media employed. Even after my Fluval completely died, I considered purchasing another one just for this feature.
  • The "quick disconnect" design is the best on the market. Very easy to use 


  • Reliability is a significant concern
  • The filter is oddly overpriced. For some reason, the price increased by almost $100 between the 04 and 05 line, when the only difference in the filters is the color.
  • The priming mechanism is not well designed or made. Especially with the restart problems, it is only a matter of time before it becomes useless.
  • Filter is prone to leaks from the motorhead (the motor head can get a slight lift as pressure builds up in the filter). I had to use silicone tape wrapped around the motorhead, right on top of the seal ring, to maintain a leak free filter.
  • I don't know what purpose the long sponges serve. I never removed much gunk from them when cleaning the filter, certainly nothing compared to what is removed from the first layer sponges in the Marineland C-Series (on the same tank) or even the Eheim 2217 sponge (with an Eheim 2217 replacing my failed Fluval, on the same tank).

Other information:

  • I've tried everything to resolve the "Fluval Restart" issue, replacing every replaceable component. At best, the results were temporary. There are far to many reports of this issue for it not to be a symptom of a faulty design.

Recommended Maintenance Procedure:

  1. Fill two buckets with tank water
  2. Unplug the filter
  3. Engage the shutoff and disconnect the valve block
  4. Carry the filter to the sink
  5. Unhook and remove the motor seal head.
  6. Remove each media container, dumping the contents, one at a time, into the first bucket (this becomes the "dirty water" bucket, swirling the media around by hand to clean it, then placing the media back into the tray, placing the tray into the second bucket.
  7. Remove the sponge filters, rubbing them clean in the bucket of "dirty water"
  8. Carefully remove the impeller cover and the impeller
  9. Rinse the impeller clean, scrubbing it with a toothbrush
  10. Using a toothbrush, q-tip, or rag, clean the impeller housing
  11. Reassemble the filter, placing the motorhead back on and latching it down. For the last two years, to get the filter to restart, I had to overfill my filter with dechlorinated water prior placing the motorhead back onto the filter, instead of allowing the autoprime to work.
  12. Carry the filter back to the tank, reconnect the valve block and disengage the shutoff
  13. Pump the primer a couple of times to force water into the impeller housing (another effort to limit the "Fluval Restart" problem)
  14. Light some incense and perform some buddhist prayers, hoping the filter is going to pump water
  15. Plug the filter back up and see if your prayers have been answered.

Posted: 3 years 10 months ago by toom #45601
toom's Avatar
With 21 watt the 405 would be the counterpart of the Eheim 1200XL that uses 25 watt with 320 GPH flow but loaded with media not pure pump power without Media....

That poor little fluval never had a chance :snicker:
Posted: 3 years 10 months ago by Oscarnewby #45596
Oscarnewby's Avatar
Have you had any experience with the newest line of Fluval canister filters? I have an 206 that seems to be doing great with no issues at all.
Posted: 5 years 8 months ago by kmuda #631
kmuda's Avatar
I certainly hope it stays that way. I was really hoping the redesign of the impeller housing on the "06" line solved the problems as I really like the tray layouts in these filters, but it does not appear that way. You may want to review the below thread for details.

The last page of the above thread contains the following input:
on page EN03 of the 06 series manual it states that the "magnetic impeller", "impeller well","ceramic shaft", and "gaskets" are to be replaced yearly. They sell a kit that contains these items for about $30.

Which would appear to be more of a necessity than a profit generator (based upon other inputs in the thread). I will add that I've been running the same impeller, shafts, and gaskets in some of my filters for 20 years. None of them are Fluvals though. My only Fluval (a 404) lasted a total of three years. The first 6 months it was fine and then it started to slowly develop the dreaded restart problems, which became progressively worse over time.
Posted: 5 years 8 months ago by yamahappy #629
yamahappy's Avatar
" 306 " is / has been very good , simple , easy to use with no priming issues at all ...