QUESTION: Do Bio Wheels really work?


ANSWER:
There is a lot of information about bio wheels and their importance in bio filtration in aquariums. In theory they are great idea and 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 oxygen the aerobic bacteria need to remove ammonia and nitrites is much more abundant. Unfortunately oxygen is not the only requirement for nitrifying bio bacteria; you also need surface area which bio wheels do have although often not nearly as much as many aquarium sponge media or ceramic bio rings. You also need nutrients and often the bacteria in bio wheels are not exposed to enough nutrients.

But after many a wheel stalling with the many customers I serviced aquariums for and after I was challenged by another person in the maintenance business after telling him I was thinking of adding some large bio wheel systems to a couple marine tanks, he asked me if I ever tested them against other filters (he had performed such tests). I decided to start testing these wheels vs. other bio filter methods.

In a more limited test, I removed the bio wheel on penguin filters on comparable (60 gallon) established aquariums with comparable bio loads and fish and found no discernable ammonia spike. Yet when HOB filters that had running Sponge Pre Filters attached to their intakes were removed, there were discernable ammonia spikes.

In another more extensive test, I ran some tests 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 lower ammonia spike.

Both these test were not performed under the best of scientific scrutiny, however they certainly gave an interesting snapshot of the effectiveness of different bio filtration types

This is not to say a bio wheel does not work at all, especially 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 in test and yet they are sealed filters (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.

SUMMARY;

This NOT to say bio wheels do not work! 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 or Whisper, the Bio Grid on a Via Aqua VitaLife, a pre filter on any HOB filter, a separate sponge filter or 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.

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 filter medias with higher surface area than bio wheels such as many quality sponge filters, volcanic rock, 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, Bio Home 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

For more aquarium information, please visit this site: “AQUARIUM AND POND INFORMATION”