The Canister Filter – A Thing Of The Past Or Still Useful?
July 14, 2008
Technology marches on and there are quite a few devices that are available for use with a marine system. The canister filter is not new and has been with us for a considerable period.
Canister filters are made by quite a few manufacturers. They are usually shaped, err, like a canister, though there are models available that are square. As time has passed they have become very reliable.
A canister filter could be considered a closed circuit. Seawater is delivered to the unit down a flexible tube, passes through the canister media and is then returned to the aquarium through another flexible tube powered by a built-in pump. It is best if the intake and outlet are at opposite ends of the aquarium, though perhaps this is not so important nowadays when the high flow rates within the aquarium are considered. Nevertheless, it is best to keep the intake and outlet apart.
What can the canister be used for? Biological filtration is the first use that comes to mind. Though filtration this way has been superseded by live rock an aquarium can still be successful using a canister, and many aquarists still do. The cost of live rock is high, and so canisters find a use. They need to be filled with a good bio-media, and this media needs to be protected by efficient mechanical filtration, such as sponges and filter wool. The cleaner the bio-media is kept, that is, kept clear of sediment, the better. The canister needs to be sized to the size of the aquarium, and the manufacturer’s specifications will include recommendations. One point about these recommendations – the flow rate advised by some manufacturers is often with the canister empty, when it is filled with media it will be less. Consideration can be given to using two smaller canisters so there is a backup. The canisters can be serviced alternately.
Cleaning the mechanical media in the bio-filter is important otherwise the seawater flow will decrease. It is a good idea to clean this media after two weeks. It may be that it remains reasonably clean in which case increase the period to three weeks and so forth. Sometimes it is recommended that the filter should be cleaned when there is a noticeable reduction in the flow rate. This is not really acceptable because for this to happen the media will be very dirty. By cleaning and checking the condition of the mechanical media the aquarist can arrive at a reasonable service period. A watch should always be kept on flow rates even with more regular cleaning because of the importance of bio-filtration – a failure or reduction could result in serious consequences. In addition, the bio-media itself must never be washed in tap water as this will kill the bacteria. If cleaning is essential then seawater should be used, and this can be at a routine change using the old seawater. The media should be very gently stirred with the fingers under the seawater to remove dust and debris. It will never look ‘as new’ but this doesn’t matter.
If the filter is used for bio purposes then the seawater leaving the filter will be low in oxygen. This is because the bacteria that carry out the bio-filtration function are oxygen hungry. The oxygen can easily be replenished by releasing the returning seawater at the surface.
There is an important point with bio-filtration in a canister filter. This is that the ‘Nitrogen Cycle’ will arrive at nitrate and stop. The ‘Nitrogen Cycle’ is the process where bacteria convert ammonia to nitrite, then the nitrite to nitrate. A watch should be kept on nitrate levels, though this should be done in any marine system anyway.
If other means of bio-filtration are in use then the canister is not redundant. It can be used for purely mechanical purposes, that is trapping detritus that is in the seawater. In this case only mechanical filtration such as sponge and filter wool are in use, and these can be washed under the tap. If they are showing any deterioration they should be replaced. This of course also applies to the mechanical filtration within the bio-filter.
The canister can also be used for activated carbon and/or anti-phosphate media. These are put in after the mechanical filtration. Certain anti-phosphate media types with a very fine particle size are usually better in a fluidized reactor, as in a canister they could tend to clog. Cleaning the mechanical filtration area is the same as above, and a note should be made of when the activated carbon and/or anti-phosphate media are due for renewal.
There is another use for the canister. If a small canister set up as a bio-filter is kept running on the display aquarium, or better the sump as connection is easier and the intakes/outlets will not be seen, then a permanently ready bio-filtration unit will be at hand. This is useful for those aquarists who have wisely used a small aquarium for quarantine purposes. This could be required again for quarantine of a new arrival, or as a hospital area for a fish with a problem. There isn’t a need to keep this aquarium full of seawater, but if required it can be filled and the bio-filter is ready.
So the canister filter is not out of date. Modern types are very reliable and much easier to service than the older models, which could be fiddly. Having a canister in the system could certainly be useful.
Aquarium Filter Media – Is There Such A Thing As The Best One
July 8, 2008
The function of the filtration is to ensure that the relevant nutrients in the water are processed. These nutrients occur due to the inhabitants being kept in a closed environment – the aquarium.
Of course life in the ocean also creates waste yet the ocean is so vast that the waste/nutrients are controlled. Look at the oceans filtration – huge sumps, loads of live rock, the biggest deep sand beds ever, mangrove swamps etc.
In our aquariums fish and food are the biggest problems. As soon as you add fish to the aquarium there is a requirement for you to feed it. The trouble is the majority of aquarists unfortunately overfeed. Not on purpose I hasten to add feeding is a pleasurable time and as aquarists we all want to ensure that our fish are well fed.
Fish being fish though will just eat. This is a natural response and is primarily because they do not know when their next meal will come, therefore the gorge.
This causes the problem. There is a lot of food which does not get eaten and starts to decay, other food is passed through the fish’s digestive system either un-digested or partially digested as they ate to much, normal faeces plus urine.
Unless this waste is broken down and processed by the aquariums filtration system then before long the fish will be living in a nutrient loaded soup.
Not nice as I am sure you will agree.
This is why it is so important that a good filtration system is implemented. There are various types of filtration which can be utilised in the aquarium some of which are listed below:
- Canister Filter
- Internal Filter
- Fluidised Filter
- Plenum
- Deep Sand Bed
- Live Rock
In the above examples there are some of these which require filter media. Filter media can be many things – sponge, ceramic rings, plastic balls etc, however it can also be sand or even rock. For example the filter media used in a deep sand bed is the sand itself and the filter media used in live rock is rock.
There are a lot of people who see filter media as being something which is man-made which is added to the aquarium. It is of my opinion that filter media is anything where the required bacteria can function.
Any type of filter media can and will work. The issue is not about where the bacteria live it is how the filtration itself is maintained and how efficient the filtration is.
A good example of this is a sponge filter media. When the filter media is working efficiently the sponge will be clean and not clogged in any way, however over time the sponge if not maintained correctly will become clogged and the efficiency of the filtration will decline.
Another example would be live rock. If the live rock is not kept clean by either manual methods or by the introduction of a natural clean up crew then the filtration may not work at a level of efficiency which is could do if it was clean.
I do admit that there are some filtration media which does allow for more nutrients to be converted. The majority of filtration media finishes at the creation of nitrate. A deep sand bed, live rock or the two combined when maintained correctly will allow for the processing of nitrate as well.
Maybe the article should have been titled ‘Aquarium Filter Media – Which is The Most Efficient’ as it is of my opinion that there is no such thing as the best filter media…just the most efficient.
Save Money and Have Fun By Making Your Own Live Rock
July 2, 2008
Live rock is a wonderful bio-filtration media. The shapes of the individual rocks are attractive and very useful in the construction of an ‘open’ reef structure. There is a disadvantage however, and that is cost.
Though different types of live rock vary in weight, this weight causes transportation to be expensive. In addition, the rock is usually transported uncured, and further cost is added for the curing process (curing is where organisms that are dead are dying are cleared from the live rock so that pollution will not occur).
Another downside to live rock is the collection itself. Hopefully collection is done responsibly and only rubble and other loose rock is collected, and nothing is prised from the reef itself. There are companies that are creating live rock in the wild by leaving non-reef rocks in the sea near a wild reef until the rock is seeded. This has to be applauded, but the cost of transportation is still there.
There is a way that hobbyists can get around the high cost of natural live rock and that is to make it themselves. There are two ways to do this.
The first way involves the purchase of live rock from the retailer. However, the quantity is ¼ to ½ of what would have been purchased if the aquarium were to be furnished with all natural live rock. When the live rock goes into the aquarium, the shortfall is made up with inert porous ordinary rock. Given time, this inert rock will become live – bacteria will take up residence and other marine life will also do the same. It is a very satisfying process but is slow and that certain virtue is required – patience. 6 months plus is the time scale being looked at. If the aquarist is to use live rock as the sole bio-filtration method, for a period care is needed to make sure there is sufficient bio capacity for the livestock. It could be that if the aquarist is concerned about the size of the bio load a canister filter could be incorporated to assist for a while. When the canister filter becomes redundant it can be used for mechanical filtration.
The second way is to make the rocks themselves. This is not as difficult, or perhaps as silly, as it could sound. For this method a link is provided so that the idea can be investigated:
When at the website, expand the ‘How To Pages’ on the left hand side list (click on the + sign). Then click on ‘Aragonite’ or ‘Aragocrete’. A list will appear and a selection can be made.
It would really be good to view a healthy, vibrant fully stocked captive reef and be able to say ‘I made that, entirely, A to Z.’
The Fun Begins – Aquascaping
June 28, 2008
It can seem endless waiting for the aquarium to ‘happen.’ All the equipment to research and obtain never mind the mounting cost that always seems to be more than estimated. Nevertheless, the aquarist knows when the really exciting time is close as thoughts of aquarium interior design arise.
It may be a fish only system that is being considered, or a full-blown captive reef. Whatever, there are some considerations that must be applied, and other aspects can be the aquarist’s free hand.
The aquarist needs to decide, or maybe already has, what type of rock is to be used. Is it going to be live rock, or will it be porous and inert rock? Whichever, the aquarist needs to ensure that there is sufficient rock to complete the structure in mind. In addition, if live rock is to be used then there must be sufficient of high enough quality to ensure the filtration of the aquarium will be adequate.
Seawater flow in the aquarium is very important. Good movement ensures that there is good gas exchange at air/water interfaces. Flow throughout the rock formation is important as oxygenated seawater is available everywhere and the chance of stagnant areas is minimised. It also means, in the case of live rock, that the beneficial bacteria can inhabit more rock areas thus increasing available filtration (subject to available nutrients). So the first item to be kept in mind is that the rocks should not be tightly packed but more of a loose formation, though of course they need to be stable. Naturally obtained rocks are usually very random in shape and this is of help – it would be difficult to pack them closely together.
Another point to be kept in mind is that livestock need a home where they can feel secure. For example, fish need somewhere to retire for the night. It is a good idea to try and build in a cave or two as construction proceeds. As already said, it is likely that the rocks themselves, being randomly shaped, will create crevices and channels.
It is great fun creating a rock formation or reef. Of course, the aquarist with a nano aquarium will have less scope than someone with a much larger one. The small aquarium may take very few pieces of rock, but it can be surprising just how many formation variations can be tried with those few rocks. The larger aquarium can have a formation much more like a reef (whether a captive reef is intended or not), and the very large aquarium provides the freedom to really be creative.
Quite a few aquarists create a reef which is well constructed and interesting. These reefs go from one side of the aquarium to the other, and their top and front surfaces are generally straight. There’s nothing wrong with that, and if the aquarist wants that kind of construction then fine, so be it. However, these reef types have been likened to a greengrocer’s shop with the vegetables (corals) laid out. If the aquarium is fairly large, that is not a nano, why not slope the reef from one side to another, or run it flat and then let it drop away before it gets to the other end? In a large enough aquarium, the formation could start high, drop down lower in the middle then climb up again at the other end. The centre could pull back from the front glass to give some swimming space. In a larger aquarium, a central but offset pinnacle could be used, with a decorative sand bed around it. Or there could be two pinnacles, again with decorative sand around the bottom. As said, it depends on the size of the aquarium, but there is scope for imagination whatever the size might be.
The aquarist is going to look at his/her creation a lot in the future, so time spent in the initial construction of the reef is time well spent. Anyway, as said, its fun!
I’ve Got Bio-Balls, Will I Be Ok?
May 27, 2008
No, no, you’ve got the wrong end of the stick! It’s not some horrible problem at all, but to do with aquariums.
Marine aquariums need bio-filtration, and this is provided by bacteria. The bacteria of course need a place to live and to avail oneself of this free service from nature the aquarist must provide them with a suitable home.
The bacteria operate what is called the Nitrogen Cycle, either fully or in part. To operate in part is easy, all that is required is plenty of oxygen plus ammonia and then nitrite. The bacteria will change the ammonia to nitrite, and then the nitrite will be changed to nitrate. Ammonia and nitrite are toxic, and nitrate much less so.
To support livestock it is enough to do only as in the previous paragraph. The toxic ammonia and nitrite are dealt with. Nitrate is left and this should not harm anything at very low levels.
However, the levels will slowly increase beyond the guideline (for a reef system) which is 10ppm (parts per million) or less. One way of reducing the level is with routine seawater changes. These changes are good for other reasons and should be completed, however nitrate could increase in spite of them. Nitrate increases are not desirable as the appearance of nuisance algae may occur.
Nature has a remedy but it cannot occur where there is oxygen present in any normal amount. The bacteria that reduce nitrate need an environment that is very low in oxygen – this forces the bacteria to extract oxygen from the nitrate thus removing it (it converts to gas and escapes the aquarium).
So bio-balls are a good medium for oxygen hungry bacteria, but not for bacteria that deal with nitrate.
If nature is going to assist with nitrate reduction, a denitrator (a so-called nitrate ’reactor’) could be used. Better, live rock can be used. Live rock has surfaces that can be used by oxygen needing bacteria, and well inside are areas for the nitrate bacteria. Live rock with a DSB (deep sand bed) is even better.
So if an aquarist is using bio-balls the answer is yes, it will be all right, except that the bacteria will produce nitrate and that will be the end of nature’s assistance.
If bio-balls are in use in addition to sufficient live rock (and perhaps a DSB) then the bio-balls can be removed, but remove them a few at a time over a period of weeks. This will allow any bio-load that was supported by the balls to be taken up gradually by the other media.
If the bio-balls were the only media, then none must be removed straightaway. Introduce sufficient live rock into the aquarium, wait a week or two, then commence removing the bio-balls a few at a time as already described. It would be of little use introducing, say, a canister filter for bio-filtration as the end product is the same – nitrate.
A good few years ago bio-filtration methods included balls. Times have changed.
If A Fish Dies Should You Remove It From The Aquarium
May 18, 2008
Quick post this evening I’m afraid as I am limited for time.
Again today’s post comes from a question I was asked a while ago.
‘If A Fish Dies Should You Remove It From The Aquarium’
To me you should only remove a deceased fish from the aquarium if you can see it and do not have to dismantle to much rockwork to get to it.
If you cannot see the fish then I would not be tempted to remove the rocks in an attempt to find and remove it. For all you know it might actually not be dead but just hiding or swimming around under/behind the rocks. On top of this by moving the rocks around you may damage some of the other fish, corals etc in the aquarium.
In an aquarium a deceased fish will decompose quite quickly. There are a lot of animals in the aquarium who will ‘eat’ the dead fish and before long there will not be anything left.
What I would recommend however is that you should check your water quality more frequently for a while using water test kits to ensure that there is no detriment of water quality.
Have You Ever Looked At Your Aquarium In Natural Daylight?
May 17, 2008
My aquarium is lit by metal halides therefore the light provided is quite bright. I use 14K lighting as well as supplemental actinics.
Normally the aquarium does not receive any natural daylight as blinds have been installed to prevent this, however the other day whilst I was doing my maintenance my wife opened them to do some cleaning. With it being a bright sunny day as soon as they were opened the aquarium was bathed in natural sunlight. As said my lighting is quite bright but as soon as natural daylight landed on the aquarium I could not even see it. It was totally masked by the sun.
Having a closer look at the aquarium I saw things on the rocks which I have never seen before. It was amazing how different it looked. The rock in particular looked phenomenal and the colours in the fish to me appeared brighter.
I appreciate that the lighting we provide is to emulate the light that the corals receive at a given depth. I believe this is 30M but I am not 100% sure at this moment in time. Obviously in our aquariums they are not this deep so you would expect a difference but I did not expect this amount of difference.
Needless to say the maintenance stopped and I sat staring at various aspects of the aquarium. After a while my wife must have finished cleaning or whatever it was she was doing and shut the blinds. Suddenly I could see the aquarium as I normally see it and to be honest I think I prefer it in natural daylight.
One of the things my Dad wants to try is to keep an aquarium which is lit purely by natural daylight. I personally believe that the aquarium will get a lot of algae but my Dad believes that he can control it.
You never know he might some time get time to try this. If he does you can be sure that we will let you know.
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