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

What Else Can You Use Instead Of Live Rock In The Home Aquarium

Live rock is very effective and efficient when it comes to saltwater aquarium filtration however dependant upon the size of the aquarium can be quite expensive to purchase.

There are, of course other filtration methods you can utilise in the saltwater aquarium. These range from deep sand beds, plenums, canister filters to name just a few.

So if you are put off by cost or are looking to utilise another type of filtration then what else can you use inside the aquarium to provide hiding places for fish and places to attach corals to.

It is probably best if we split this into two sections – one based around cost and the other around using alternative filtration methods.

First let’s have a look at cost. As said to provide enough live rock in the [tag-ice]aquarium[/tag-ice] can become quite expensive if the aquarium is of a large or even medium size. The main reason for this cost is that the majority of the live rock sold is what is called premium quality i.e. it is covered in coralline algae, has lots of life on it etc.

If you think about it the quite a lot of the rock which you place into the aquarium is not going to be seen by you – it is going to be hidden by other rocks. So why pay for the expensive stuff if you are not going to see it.

Why not use base rock. This is exactly the same as live rock and is full of the required bacteria required to perform the filtration but is lacking the coralline etc which makes it look nicer. Base rock is a lot cheaper than premium rock. Quite a lot of people (myself included) purchase about 75% of the required rock as base rock and then the remaining amount as premium quality.

What I do is only use the premium rock on the face – all the other rock in the aquarium is base rock. I have not lost any of my filtration capabilities and over time the base rock will become covered in coralline like the premium rock.

I personally prefer the above method when you are filtering the aquarium via live rock. There are other methods as well which you can use but one thing you must do with these other methods is to ensure that you are providing the required amount of filtration necessary for your aquarium size and bio load.

The second part of this article can cover both areas i.e. saving money and providing filtration via alternative methods.

Personally I believe that there are realistically three options available to the aquarists.

The first one is to use a product which is commonly known as [tag-tec]reef bones[/tag-tec]. Reef bones is basically rock which once used to be live. This is normally removed from places like the top of caves where they are cleaned and prepared ready for home aquarium use. If you are using live rock then they can be used as a base. If you are using another method of filtration then they can be used in the aquarium for decorative purposes as well as providing cover for fish and places to attach your corals to. Over time reef bones starts to look very natural – actually it looks just like live rock. It gets covered in [tag-self]coralline algae[/tag-self] as well as other growth found in the home aquarium. Over time these reef ones may again become live.

The second method is to make your own rock. I personally have never tried this but have been tempted on occasions (just to see if I could do it). A lot of people are reporting success using this method and the good thing is that you can make your own rock to the exact shape and size you want so that you can aquascape your aquarium exactly how you want it. A great place to check out if you are interested in making your own rock is http://www.garf.org.

The third method is to use another type of marine safe rock. When I say reef safe I mean that it does not contain anything in the rock which may leach out into the water and be detrimental to the health of the inhabitants for example metals, pollutants etc. Some aquarium shops sell rocks which have been prepared for the home saltwater aquarium. I would recommend that if you are interested in this method that you check that the rock is reef safe before adding it. I would also recommend that you bathe it in freshwater for a while prior to adding it to the aquarium so that any aspects which may be in the rock have time to leach out.

There are a lot of people who believe that live rock is the only thing available when it comes to decorating the aquarium. The truth is that there are lots of options available. I agree that live rock is very attractive and has fantastic filtration capabilities, however live rock is not for everyone – everyone is different, that is what makes the human race so interesting.

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Tags: Aquarium Filtration, canister-filter, home-aquarium, live-rock, saltwater-aquarium