Is There Such A Thing As The Best Aquarium Filter?

Filtration in the marine aquarium supports the number one requirement, and that is water quality. Whether the system is a fish only aquarium or reef aquarium, water quality is paramount. The next most important requirement is lighting for a reef aquarium.

The question here is a little too general. Are we talking of bio-filtration, or is it mechanical and chemical filtration? I don’t know what was behind the question so let’s have a look at them all.

Bio-filtration is the major filtration need in an aquarium, so let’s start with that. Bio-filtration is where the nitrogen cycle, or part of it, takes place. That is, bacteria take dangerous waste such as ammonia and nitrite and convert it. Without this natural service keeping a marine system of any type would be difficult, expensive and not so good for the inhabitants.

The major requirement for bio-filtration (at least the initial stages of the nitrogen cycle) is oxygen. So for anything to operate well this oxygen supply is required.

The first method with this in mind is the trickle tower, where water runs down with gravity through media. This is a good method of filtration, as oxygen is readily available from the atmosphere. The bacteria are not going to have any problems. The downside is that these filters produce nitrate and that point is the end of the nitrogen cycle.

So what about that old and well trusted method, the canister filter. These filters are very reliable and the modern ones are easier to service (this used to be a bind). The bacteria are completely submerged and depend on oxygen from the seawater, so it is important for the system designer to bear this in mind, that is the water surface should be open, and in addition if possible weirs should be incorporated, or a powerhead could be directed at the surface. Additional oxygenation may not be needed in a well designed system with correct water movement. Again, the end product is nitrate.

The under gravel filter is subject to the same oxygen considerations as the canister. However, the under gravel filter is, at least in my opinion, not a good choice because of eventual problems with media blockage. This filtration will not be considered further.

Though there are other bio-filtration methods the last one to be considered in this text is live rock. Live rock is natural in that it is nature’s product. The bacterial process in any filter type is natural of course, but live rock is natural overall. Live rock in sufficient quantity and of high quality can successfully filter an aquarium. A big plus is that this method can deal with nitrate if not abused - in other words, the filtration provides the full nitrogen cycle. That is a big plus. In addition, the very fact that it is rock means that the aquarist can use it to aquascape the aquarium, and it doesn’t matter if the system is fish only or reef. The bacteria again rely on the oxygen in the seawater, so the points noted about this are relevant.

It doesn’t take a detective to discover the champion bio-filtration system here, and yes, it is live rock. The downside is that live rock is expensive, and corners should not be cut to save money with this filtration. If money is a problem, then consideration to the canister and trickle methods can be given, remembering the point about nitrate.

Right, that’s that bit covered. What about mechanical/chemical filtration? There’s not much to be discussed here.

With this filtration the aquarist requires a method that is unobtrusive and reliable. There aren’t any oxygen considerations. The canister filter is the one, and ideal for the job. They usually have compartments where different media can go - sponge of various densities and other fine filter types to trap detritus, and carbon if used. As said, canisters are easier to service nowadays than they used to be and that is the main requirement - they should be regularly serviced and any carbon changed, and detritus trapping media cleaned or renewed. The cleaning can be under a tap, there isn’t any need for caution in respect of bacteria. (Note that this is mechanical/chemical filtration. If a canister is being used for bio-filtration then cleaning under a tap the media supplied for the bacteria is a no-no, as the bacteria will be killed with dire consequences.)

So there we have it, the best: live rock for bio- filtration and canisters for mechanical/chemical filtration. This is of course my opinion, but I would hazard a guess that there aren’t many who would disagree.

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Tags: Aquarium Filter, Aquarium Filtration, deep-sand-bed, Equipment, live-rock

What Is The Best Filtration Media To Use In A Canister Filter?

Canister filters have been around for decades. They’re usually shaped like a canister (strange that) but can also be square. The media sits in the canister under the ’lid‘, and it is in or on the lid that an electric motor is placed. Water to the filter arrives via a flexible tube, and is returned by the same method. Canister filters were used, and still are, by freshwater aquarists, and have been adopted up to a point by the marine hobby.

Canister filters are very reliable though some makes, as in most things, are better than others. There are a couple of points that need mentioning. The first concerns flow rates. It is the habit of many manufacturers to quote flow rates for an empty filter. Without the media in position the flow rate will be higher, so in the real world expect the flow rate to be perhaps up to a quarter or so less. Flow rates are additionally slowed by the lift - if a filter is placed on a level with the aquarium there is little or no lift, if it is below the aquarium the electric pump has to lift water from the filter to the highest point before entry to the aquarium. It is important to know this distance and check the filter performance from manufacturer’s data.

Ok, back to the media. The question could be taken three ways. What is the best media to use in relation to a marine aquarium, the best for bio-filtration, and the best for mechanical filtration.

As far as marine aquariums are concerned, the bio-filter media of choice is good quality live rock, in my opinion. Therefore the canister filter, using this as a “rule“, would be redundant as a bio-filter. There aren’t any rules, however, and though the canister filter is not the best bio-filtration method to use overall it is not redundant in this respect. Nevertheless, if live rock is to be employed, the canister filter is demoted to mechanical filtration.

If the canister is to be used for bio-filtration, then some care on the media set-up is needed. Bio-filtration is the ‘life support’ for the livestock and obviously is very important. Though it may be against some manufacturer’s suggestions, I have found that having all the mechanical filtration in front of the bio media is advantageous. I found a fine filter, sandwiched between two medium grade sponge filters, does an excellent job on protecting the bio media from debris. It is very important that the mechanical filtration is cleaned at regular intervals (the period dependant on the cleanliness of the water, perhaps every two to four weeks). In addition to helping to keeping the bio media clean, it maintains water flow. The bio media available is varied, however sintered glass, which is in the form of small tubes, seems very good. As there are lots of channels within the glass, it can act somewhat as does live rock for a while. In other words, nitrate can be reduced by bacteria. This benefit is usually not long lived however, as fine debris does inevitably find its way onto the media causing some clogging and the anti-nitrate advantage is lost sooner or later. (This media should not be used intentionally for any anti-nitrate properties.) The media still remains very good for ammonia/nitrite filtration. The media, if cleaning is required, should be gently cleaned in warm aquarium water, never in tap water. The latter will wipe out the bacteria. A final point to note when bio-filtration with a canister filter is employed, is that the unit will usually produce nitrate (perhaps not straight away as indicated). When nitrite has been converted to nitrate, the nitrogen cycle stops. If there isn’t a low oxygen environment for bacteria to inhabit, then nitrate will remain. A check needs to be kept on the level.

If the filter is to be used for mechanical purposes, then the same mechanical filter media as above can be employed. This media can begin with medium grade sponges, perhaps two layers, and end with fine grade filters. Many manufacturers provide ready made filter materials such as sponges so the fit in the filter is good. Manufacturers usually give suggestions for mechanical filtering. In addition, activated carbon can be used in the filter. It is usually placed after some mechanical media. Activated carbon is not always a necessity, and should not be used continuously if there is a need but periodically. The media removes trace elements from the water. When exhausted (manufacturers will suggest life expectancy) the media should be discarded, if more is required it should be new. Similarly, anti-phosphate media can be used. This can be used continuously if necessary, changing the media at the manufacturers recommended periods. Some anti-phosphate media has a tendency to clog and/or channel, making it far less useful. The types that do this are usually the ones with very fine media.

So the canister filter is useful to the marine aquarist. It is not ‘number one’ for bio-filtration, but can still be used as such, with success provided the aquarist maintains it properly. The filter is also useful for assisting in the removal of debris from the seawater etc. Some aquarists, having a canister filter available and not requiring filtration from it, have experimented with other media, such as small pieces of live rock debris and very coarse sand. I don’t know the results of these experiments, but I do know that in my canister filters using standard media, when doing maintenance I always have to remove very small shrimps and snails and return them to the aquarium.

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Tags: Aquarium Filter, Aquarium Filtration, canister-filter, Equipment, saltwater-aquarium

Why Is Aquarium Filtration Such A Hot Topic

The marine aquarium hobby was once viewed as very hard, very expensive, and needing a touch of magic. The first two were correct, but not the latter, that simply being how it probably appeared to anyone not in the hobby but perhaps with a spattering of knowledge. There was little knowledge of the needs of captive marine life, and for the most part (the biggest most part) only very hardy life in very small numbers survived for any length of time, and that was usually measured in months. [Read more]

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The Canister Filter - Any Use In The Marine Aquarium?

The canister filter has been in use for decades. Freshwater aquarists were the first to make use of them and they still do. Then along came the marine aquarium and the canister filter was employed to support those to. Canister filters have been around for so long that they are now very dependable and failures are rare. [Read more]

Tags: filter-reef-tank, filtration, live-rock, nitrate, saltwater-aquarium