QUESTION: Do Bio Wheels really work? Bio Wheel Review & Controlled Tests
Updated 2/4/13
ANSWER:
A Little Background

There is a lot of information about bio wheels and their importance in bio filtration in aquariums. In theory Bio Wheels are a great idea and admittedly I bought into this idea for years without testing the results to see if the hype was true.

In theory the wheel turns into the air where the oxygen that aerobic bacteria need to remove ammonia and nitrites is much more abundant than in water. Unfortunately oxygen is not the only requirement for nitrifying bio bacteria; you also need usable surface area. Bio wheels generally do not have as much useable surface area as other aerobic bacteria bio surfaces such as Sponge media or suspended (fluidized) sand media. You also need nutrients, and often the bacteria in bio wheels are not exposed to enough nutrients. It is also noteworthy that a dissolved oxygen level of 5-7 ppm that a properly circulated/aerated aquarium should have, is ample oxygen for nitrifying bacteria.

Later, after many bio-wheels stalled and I was challenged by another knowledgeable person in the maintenance business to test them against other filters (he had performed such tests and knew the answer). I then decided to start testing these bio-wheels versus other bio filter methods.

Tests, Further Information


In my first and more limited test (this is the test my colleague had performed), I removed the bio wheel penguin filters on comparable (60 gallon) established aquariums with comparable bio loads and fish and found no discernible ammonia spike.
Yet when HOB filters that had running Sponge Pre Filters attached to their intakes were removed, there were discernible ammonia spikes. What this means is that the Bio Wheel was not the primary source or even an important source of bio filtration for the tanks with the bio wheels. In other words these tanks were maintaining whatever bio filtration they had via other means such as gravel, filter cartridges, etc, while the aquariums with the Pre-Filters (& a couple with a sponge insert) had these bio filter mediums removed, the subsequent loss of bio filtration via a discernible spike in ammonia/nitrites was noted.

The second test involved many more aquariums and was more extensive.
This second test consisted of 60 & 80 gallon aquariums (performed at my large client; Coaster Co of America which had over 20 aquariums). Goldfish and Discus aquariums were utilized, all WELL established, with the same bio load and feeding regimen.
In fact the same aquariums were re-used multiple times in this second test as I would change out filters and then wait 8 weeks prior to re-testing with a different filter (this second test went on over a 9 month span).

In these, I ran some tests with Penguin Filters (as well as Emperor Filters) with Bio Wheels against Sponge Filters, Aqua Clears and Whisper Filters with the Sponge inserts in equal established tanks fed the same amount, then added large amounts of fish food and although the bio wheels did respond, the Sponge Filter showed a lowest ammonia spike of any filter tested when only one filter was present.

Another result emerged and that is in these tests the aquariums that responded to the largest amounts of fish food were the multi-filter tanks that included a HOB Filter (such as a Whisper, SunSun Power Filter, etc.) AND a Sponge Filter which provided a good example of how much Sponge Filtration via a simple Sponge Filter can improve aquarium bio capacity.

These tests also included removal and/or replacement of cartridges in HOB Filters that had both cartridges and a secondary Bio Sponge, Grid, etc. such as the Whisper, SunSun etc. and of course the cartridge in the Marineland Penguin & Emperors.
Again, the Bio Wheel in most instances did not match these other filters EXCEPT in the case of power filters (of which there are many) that only had a cartridge; in the tests with these "cartridge only" filters the Bio wheel filter considerably out performed these rather basic power filters.

It is noteworthy that although the cartridge only filters were not as effective as the Bio Wheel Filters due to the fact that most bio colonies were removed with each change of the cartridge; HOWEVER when a Sponge Pre-Filter was added to these 'cartridge only' filters (such as a "Cheapie" Walmart filter used in this test), the HOB Filters with the Sponge Pre-Filter again outperformed the Bio Wheel Filter (a Penguin in this test).

Both these tests were not performed under the 100% scientific scrutiny (although the second was much more extensive and gave a better picture of nitrifying bacterial colonies), however they certainly gave an interesting snapshot of the effectiveness of different bio filtration types.

I might add that since these initial tests/studies several years ago, Fluidized Filters have emerged as THE superior aerobic bio filter (especially the new 3rd generation version by TMC).
Tests I ran with Sponge Filters versus 2nd generation Fluidized Sand Bed Filters showed that even the Sponge Filters (the #5 Hydro Sponge versus the basic Lifeguard FB Filter) could not respond to increasingly higher "dumps" of fish food as fast as the FB Filters could.

As well a new variation on the HOB filter has also emerged that combines the Wet/Dry, Sponge and HOB filter with many of the attributes of these three before mentioned filters and that is the Internal Wet/Dry such as the ReSun BF 100 or the filter found in Bio Cube Aquariums. These are in many ways similar to a large Aqua Clear filter, except with the ability to add external devices such as a UV Sterilizer.
My reason in pointing out these filters is that there are even newer more effective alternatives to Bio Wheels currently available that are not expensive either.

This is not to say a bio wheel does not work at all, especially if there is less build up deposits on the bio wheel fiber.
What is much more important is to have an adequate amount of dissolved oxygen through agitation of the water surface, which is where oxygen and other gasses are exchanged from the atmosphere and the aquarium. I have found a porous sponge filter media to maintain more bacteria in well oxygenated water.
This is an important point as although air can contain much more oxygen necessary for aerobic nitrifying bacteria (which is the theory behind bio wheels), the fact remains that the nitrifying bacteria do quite well at the normal dissolved oxygen level of 5-7 ppm of most adequately circulated and properly stocked aquariums.
In fact a somewhat unknown filter; the Fluidized Filter well out performed bio wheels and wet/dry filters, even Sponge Filters in later tests and yet these are "sealed" filters, which further blows the argument for Bio Wheels out of the water that states the oxygen availability of the wet/dry feature of the bio-wheel is superior for bio filtration (this comparison is based on established filters over 6 months old).

Here are a few reasons behind the poor results of bio wheels:

[1] Hard water buildup; although not as much a problem in soft water aquariums, this is a major problem with hard water aquariums and especially marine aquariums (where these bio wheels are a total waste of money). What happens is the calcium, salts and other deposits form in the pores of the bio wheel fiber, not allowing bacteria to form there. This is the main reason for the lack of effectiveness for bio wheels. My tests in Discus aquariums (which are soft water) showed better results for bio wheels (although not as well as sponge or other porous media).

[2] Lack of surface area; a bio wheel does not have the surface of many other bio media products from sponge media to the very porous pumice and ceramic media used by Eheim and others.

[3] Bio wheel stalls; bio wheels have a bad habit of stalling or rotating too slowly for the bacteria to be bathed in nutrients. This can be only a minor reason to not have these bio wheels as this is a somewhat correctable problem. Here is a way correct this problem (this will be an on going maintenance problem). Make sure the Teflon ends on the bio wheel axle are clean and have no build ups of calcium you can replace these with Teflon tape in a pinch. Also make sure the bio wheel assembly is not to tight, simply remove the bio wheel and gently stretch the assembly apart so the wheel can spin more freely.

[4] As for the Marineland Emperor Bio Wheel Filter, I have heard some unsupported arguments for this filter, HOWEVER in multiple observations where the Emperor Filter was replaced with a Hydro Sponge #5 (& smaller) or another filter along with the use of SeaChem Matrix, tank conditions improved for many parameters, most notably KH, nitrates and Redox.

WHY one might ask? This is where this observation can be answered with known science and that is the design of the Emperor filter lends itself to being a nitrate factory with its spray bar and irrigation of the basket area, not allowing the use of products such as SeaChem Matrix, de-Nitrate, volcanic rock, Bio Home, live rock crumbles, etc.
I have also found decomposition that leads to decay of KH and reduced Redox balance with Emperor Filters.

I will also note that I have found similar results with poor Redox, KH, nitrates with the use of wet/dry filters systems that employ bio balls and/or ceramic media (not so with Wet/Dry employing live rock and/or sponge filters).

SUMMARY;

This is NOT to say bio wheels do not work, they are certainly better than cartridge only filters! Bio wheels just do not hold up to the hype and urban myths about them in the aquarium hobby.

You can often do better with the sponge in an Aqua Clear, SunSun, or Whisper Filter, the Bio Grid on a Via Aqua VitaLife, a pre filter on ANY HOB filter, and especially a separate Sponge Filter and even more so a Fluidized Filter (which the Bio Wheel filters do not even come close to in bio capacity), even an aquarium sponge stuck inside a HOB filter without any other bio media.
I have used many Bio Wheel (Penguin, Emperor, etc.) filters over the years with good results, my point is again not that they do not work, just if you are purchasing one of these filters for the main reason of having a “better” bio filter, you are not making the best choice based on controlled test data.

I also want to be clear that if you already have a Bio Wheel equipped Penguin or Emperor that I am NOT advocating that you immediately trash this filter and run down to your local fish store (or online) to purchase a new filter, rather to consider their drawbacks and I do STRONGLY recommend the purchase of a filter such a Hydro Sponge Filter, Internal Wet/Dry Filter, or Fluidized Filter (the Fluidized filter requires a power head or canister filter to power it) to compliment your Bio Wheel equipped filter (which is what I recommend for any filtration system anyway; the redundancy of more than one filter!).

Finally, what is missed by proponents of Bio-wheels is although the oxygen aspect of the bio-wheel is one aspect of aerobic nitrification, it is not difficult to maintain adequate oxygen levels for most other aquarium bio filters in a properly set up tank. What is more important is surface area and there are many other specific filter medias with vastly superior surface area such as nitrifying and de-nitrifying volcanic rock, Matrix, ceramic media and MUCH more.

Another important aspect of aerobic filtration is that the faster and more ammonia and nitrites your aquarium bio filter processes the more nitrates your aquarium will have in the end. This is especially noteworthy for marine aquariums which is why I would recommend live rock crumbles, volcanic rock, Matrix or similar filter media that has deep pores to perform de-nitrification via anaerobic bacteria and why my consideration many years back of a large bio wheel system for a marine tank was/is a bad one.
The use of a Protein Skimmer in Marine tanks can be helpful in preventing nitrate buildup as well. Please see this article for more marine aquarium information: “Saltwater Aquarium Basics to advanced”

I will also state that the design of most Marineland (Penguin, Emperor Filters) are very efficient and they are reliable mechanical filters with much less flow-by than some others, most notably Aqua Clears, so with this in mind, ANY filter decision should be based on what you need out of a filter and for more aquarium information about aquarium filters: Aquarium Filters and Filtration

Another excellent article for suggested reading is "UV Sterilization, Facts & Information" which dispels many myths about use including the fact with so many low quality UV Sterilizers flooding the market, one cannot judge all otherwise quality UV Sterilizers based on the former nor based on poor maintenance such as failure to replace UV Bulbs or ballasts on a timely schedule.

Other Recommended Reference Sites

-A useful source for current Aquarium Information and Resources (Pond too). Basic and in depth articles from Aquarium Lighting; Reef, Planted, more, Filtration, Fish Nutrition, UVC Sterilization, Ich, Pond Care Information, The Aquarium Nitrogen Cycle, and much more. Well researched and up to date aquarium and pond articles, answers, help, and links. Based on 33 years Professional experience & research in Los Angeles and now in Oregon. This Aquarium and Pond Information resource is a must read for any aquarist serious about current aquatic information and articles

For a friendly, Knowledgeable, aquarium forum with in a family atmosphere, Aquarium Forum; Everything Aquatic & Board is an excellent place to go for information, help or simply to share your love of the aquarium and pond hobby and help others. A superior place for information over such places as Yahoo Answers

FISH AS PETS; Articles and commentary of Interest to the Aquarium Hobby; Such as Parasite Retailers, Are these Planaria or Detritus Worms in Aquarium, Melafix Dangers; Facts, & Celestial Pearl Danio, Galaxy Rasboras

Labels: Aquarium Bio Wheel, Bio Wheel Review, Emperor Filter, Emperor Review, Penguin Filter, Sponge Filter