Fish + Food = Fun

Keeping a marine aquarium is great. It must be, there are enough people doing it. Reef or fish only, it is a tremendous hobby being educational as well. Having some of Mother Nature’s wonders in the home is an eye catcher for visitors and sometimes becomes consuming for aquarists.

There’s maintenance of course - cleaning the algae from the aquarium glass, topping up evaporated water, cleaning and checking filters and pumps and the rest. Some aquarists just enjoy it in the same way that some gardeners enjoy weeding. Some do it because it has to be done and find it reasonably enjoyable. I’m one of the latter - it has to be done but it isn’t the favourite part of the hobby.

The best part as far as I’m concerned is looking at the aquarium. I know, it sounds just like ‘I love work; I can sit and look at it all day.’ It’s not that. Looking at the aquarium is really what it’s all about. Admiring nature in the home and feeling pleased because it’s mine and I maintain it.

There’s another bit of maintenance that’s great fun too and runs a very close second, and that’s feeding the livestock.

It doesn’t take long for fish and shrimps to become used to a feeding routine. When the aquarist approaches the aquarium, often there they are at the front waiting. Food goes in and the fish tear around making sure they get their share or more if they can.

Some fish will come to the fingers and remove food. This is really getting personal and the aquarist is normally enthralled by it. Then there are the cleaner shrimps of course. They will take food from the hand and, like fish, come close to the surface for it. In addition the shrimps will walk around on the aquarist’s hand looking for food be it feeding time or not. It must be strange for them, a queer fish with weird fins appearing but hey-ho, the food is good.

There is a potential problem with this feeding interaction however it is done. It is such a feel-good situation that it is likely that a newcomer to the hobby will overfeed. Fish and shrimps will take as much as they can possibly get when they can get it. As in the wild, their instinct is to eat quickly as they do not know when the next meal will be. Fish can stuff themselves to absolute capacity, and some of the food will be excess and will pass through the gut undigested, or only partially so. This means pollution for the aquarium which is one thing that is not needed as it will impact on seawater quality. In addition, it is impossible to ensure that all the presented food ends up inside a fish or shrimp. Some will inevitably end up loose in the seawater and will become lodged among the rocks. There it will rot, although hopefully in a reef aquarium or even a fish only one where there is live rock, all the little tiny life forms that inhabit the rock structure will eat it.

Even with the caution in mind about overfeeding it is still great fun. The aquarist needs only to restrict the food quantity to that which is known to be sufficient and stop there. Fish and shrimps are persistent beggars and the aquarist may feel that their actions indicate that more food is needed and give some. Simply don’t.

Oh, yes, and when the feeding is over don’t forget to sit back and watch the aquarium. Enjoy!

---

If you're new here, you may want to subscribe to our RSS feed. Thanks for visiting!

Tags: feeding-fish, fish-food, fish-tank, marine-aquarium, marine-fish, reef-fish

Nano Tanks Are Smaller But Do They Need Less Work?

A nano marine aquarium is one which at the smallest end is around 10 gallons capacity and at the largest around 30. They can be fish only or reef, but of course the capacity for fish and corals is restricted.

Most aquarists dream of an aquarium which is large - 6 ft by 2 by 2 is a fairly common size. These allow a larger number of fish to be kept and many more corals. The impact of a successful large aquarium is simply stunning; I cannot imagine anyone who breathes not being taken by the overall beauty.

The advantage of the large aquarium is that the aquarist has a lot to play with and, within guidelines, could create nearly anything. The disadvantage is the cost. The aquarium itself is not going to be cheap. Then equipment to service the gallonage is required = a larger protein skimmer, several and in the case of a reef more powerful lighting, more live rock, larger heaters, larger chiller etc. Stocking the aquarium will be more costly - more fish, more rockwork, more corals in more seawater. The cost goes on - dry salt for routine seawater changes, electricity costs (electricity becoming more expensive in particular). So buying a large aquarium needs some careful forethought. Going over-budget and cutting back on routine maintenance is not going to enhance the likelihood of success.

For many a large aquarium is simply just a non-starter. This is usually because of cost but can also be because there isn’t a location to keep one. In these cases all is not lost; a smaller aquarium can be just as interesting and far less costly to obtain and keep.

The apparent downside is that there will be less fish or other livestock. Clearly fish need to be suitable to the captive environment and corals need space to grow. If fish only are to be kept then rockwork is needed to provide homes. Live rock will not be so expensive. The fish kept will be small types. A shrimp could be added. Lighting is not a problem. This environment for fish will be interesting and could be beautiful, the rocks aquascaped to make the most of the space available. Watching the fish settle in and become accustomed to their home is very satisfying. There aren’t any aggressive large fish to cause the small ones to be timid so they’ll be seen often.

If the aquarist wants a reef then it is obvious that it is going to be small. A reef of live rock can be constructed in a small aquarium, though the smaller ones look better with just three or four larger rocks carefully arranged. Fish choice is limited to one or maybe two small ones as seawater quality must be high and fish place the greatest pressure on this. The choice of corals must be completed cautiously, as large corals are not best placed in small aquariums. However, soft or hard varieties could be kept with their number restricted and positioned with care. Suitable lighting is required of course, and in a small aquarium it is more likely that fluorescent T5 tubes could be adequate. If metal halide is used, then bulb wattage will be minimal thus reducing running costs.

That is the biggest advantage, running costs. With smaller heaters and lighting system etc electricity will not be the potential monster it could be with a large aquarium. Routine seawater changes will not be many gallons so dry salt will last a long time, and supplements likewise if used.

A nano aquarium could be constructed piece by piece by the aquarist, or alternatively there are now a good few companies marketing ‘plug in’ versions. With these the aquarist will have less time to wait for the aquarium to be ready for livestock, though that prerequisite for marine aquarists - patience - remains important.

So the nano aquarium is less costly to run and stock, but what about ongoing maintenance? All the jobs of the equivalent large tank, fish only or reef, have to be completed. The routine seawater change needs to be done (but being less gallons a smaller and more manageable container is suitable). The lights need to be changed at recommended intervals (the cost will be less). Seawater parameters require routine testing as on a large system (no difference). The aquarium glass needs to be cleaned regularly (being smaller the job will take less time). Livestock needs to be observed for health (there are less so this also takes less time). All the jobs of the large aquarium are needed, there will not be a saving in this (except in cost), but the time the jobs take could be less overall.

There are some really lovely nano aquariums about. They admittedly do not have the impact of a large display, but get down in front of them and they suggest a small part of a reef. The beauty is not in any ‘ooh’ and ‘ah’ but in the detail that develops.

---

Tags: Care, Equipment, marine-aquarium, nano-tank, pico tank, reef-tank

Stress Is One Of The Biggest Killers

As the title of this post say stress is one of the biggest killers to both fish and corals in the home marine aquarium. Next to this will probably be bad maintenance and mis-management of the aquarium and last but not least will probably be laziness.

I remember as a child my dad being able to make up and read some great stories which brought my imaginative little mind into action!

Below is a little story that John has made up recently which I believe describes stress in marine fish exceptionally well.

“Out on the coral reef, thousands of miles from Europe, an angel fish has been caught and is now in an open topped holding tank on a boat. At the end of the day the boat makes its way to shore. The fish is taken out of the holding tank and placed in a bigger tank with many other fish.

After some time, the angel fish is taken out of the tank and placed in a bag, which is tightly wrapped. The bag, with many others, is placed into a large polystyrene container. When the container is closed, the fish is in darkness. Very highly stressed, it sits there.

The container sits around with others, and eventually, (hopefully with minimum delay but this cannot be certain), it is put into the cargo hold of an aircraft. Again hopefully, the aircraft takes off on time for a long journey to Europe.

On landing, the aircraft is unloaded and the container sits around in a much cooler climate awaiting customs clearance. This takes a little time, but fortunately the officials are aware that livestock is involved and delay is more or less minimised.

Off goes the container in the back of a large van, destination the main distributor. On arrival, the container is taken into the building and once again some delay occurs. The wholesaler is well organised, and turns lights off, switching on low powered red lighting. The container is opened, and the angel fish senses light for the first time in many, many hours. It is a good thing it has arrived, as the water in its bag is cooling, the pH is dropping, and the oxygen is low. Into a holding tank goes the fish. After some hours, the main lights are put back on.

The wholesaler inspects the fish. It hasn’t done badly, all things taken into account. It is subdued, and breathing rather rapidly, but should be alright.

After a day, a little food is offered, which is taken. The fish is swimming about.

A dealer arrives, looking for fish for his local marine shop. He looks at many fish, but doesn’t choose the angel fish.

The wholesaler catches the angel fish and puts it into a bag, then into another polystyrene container, but this time a smaller one. The wholesaler has received a telephone order from a marine shop two hundred miles distant. The container is closed, and once again the angel fish sits in darkness.

The container is put in a van belonging to a postal company. The journey is slow as traffic is bad, and the driver also stops for lunch.

On arrival, the container is removed. Half an hour later, it is opened. The bag with the angel fish, along with others, is taken out and left to float in the dealer’s tank. Not before time, as there is a leak, and the water, deteriorating in quality, was also getting low.

The dealer is pleased, as the angel fish feeds quite quickly. It also slowly swims round the tank with the other fish. Nowhere much to hide, and not much space to swim in.

It is Thursday and Jim, who has kept fish for a few years, comes into the shop. As usual he has a coffee with the dealer as they put the world to rights. Then off he goes to have a look at the delights in the display tanks.

Jim looks at the angel fish very closely. He has always fancied one of these beautiful creatures. He knows it will be suitable for his aquarium. Jim doesn’t hurry, however. He watches the fish swim, watches it breathe, examines the body and fins, also the eyes. The angel fish seems fine. After a little discussion with the dealer, the angel fish is caught, put in a bag, and is on its way to a new home.

At home Jim is very excited. He has a really stunning angel fish. He also knows that he must be careful. He turns off the lights, opens the bag, and runs a drip into the bag from his aquarium, after floating the bag in the aquarium for 15 minutes.. He allows the bag to fill three times, discarding half the water each time. The angel fish is then gently released from the bag into the aquarium. After going in a slow circle, and moving along the length of the aquarium twice, the fish goes into the rocks. Jim leaves the lights off. In bed, having read so much about the angel fish species when considering if he should purchase one, he reads the book once again.

In the morning, before the lights come on, the angel fish is out of the rocks slowly moving around the tank. The light come on in a ’dawn’ sequence, blue first, then halides. The angel fish retreated to the rocks, but was fine. The angel fish and its new companions have no problems. The angel fish feeds, too. Now Jim’s collection is complete.

Nine days later, Jim notices the angel is lethargic. Nothing can be seen to warn of problems. But is it breathing rather quickly? Can’t be sure. Nothing changes, but three days later, Jim notices the angel fish resting against a rock, breathing quickly. There is something wrong! But what. Jim studies the angel fish with care, and thinks the fish may have a dull body. What to do? Jim decides to bring the fish close to the front glass to examine, but as he puts the net in the angel fish disappears into the rocks. Jim doesn’t dismantle his carefully built reef. He never sees the angel fish again.

Distraught, Jim decides it was ‘one of those things.’

Five days later Jim notices that a fish has a‘sheen’ on its skin. Then he notices another. They are breathing rapidly. Then he notices another. Out comes the book. He decides the problem seems to be ’velvet’. Thank goodness it can be treated.

Then it becomes clear the treatment is copper sulphate. It cannot be used because of the corals in the tank.

Jim tries a ’reef safe’ cure, but loses six fish. Three survive.

If there had been a quarantine tank, the likely ending of that little tale could have been a happy one. The angel fish, kept in the quarantine tank, could have been treated with copper and cured. After a period to prove the health of the fish, it could have gone in the main display aquarium and had a long life. Nothing is copper-bottom guaranteed, but the chances are the happy ending would have occurred.”

---

Tags: aquarium, aquarium-fish, marine-aquarium, marine-fish, reef-fish, reef-tank

Hands In The Aquarium - We All Do It

Whatever aquarium type it might be, fish only or reef, large or nano, aquarists put their hands into the seawater.

Maybe a rock is out of place and needs to be adjusted, or a coral is crowded and needs to be moved. Perhaps the aquarist is having a war with aiptasia anemones and is in the middle of one of the skirmishes. Or perhaps a life form of some description is being removed.

Care is always needed, though for the most part all is usually well.

Click on the link below and have a read of one aquarist’s experience with what seemed to be innocent…

http://www.fishforums.net/content-page/79056/pagination/page/0/

---

Tags: Aquarium Maintenance, Care, marine-aquarium, reef-tank, saltwater-aquarium

Aquarium Water Is Just Water Right - Wrong!

When keeping an aquarium - be this coldwater, freshwater, marine etc then there is one thing you are definitely going to need other than the aquarium - water!

Sound obvious doesn’t it?

Well let’s face it if we don’t put water in the aquarium nothing is going to survive is it - it’s not as if you can fill it with custard!

But water is just water - isn’t it?

The answer to this is both yes and no. It is correct that water is just water in the sense that it is wet however the substances which is in the water is what makes the water we want to use in our marine aquariums different.

In home water various additional substances are added to it in order to make it safe for human consumption and also various other aspects which get into the water by, for example, agricultural practice (phosphates, pesticides, nitrate etc).

It is for this very reason that the majority of aquarists use reverse osmosis water.

There are various other techniques which people also use - natural sea water, deionised water etc, however normally reverse osmosis is the water of choice for the majority of saltwater aquarists.

So what is reverse osmosis?

Basically a reverse osmosis unit is a device which is attached to the home water supply and this water is then pushed through a semi permeable membrane with pores so small that only water will pass through. It then also passes through other chambers where the majority of other substances are removed.

Generally the reverse osmosis process is 95% or higher in efficiency. The end result of the reverse osmosis process if water which is safe for aquarists to use in their saltwater aquariums.

There are a couple of things which need to be noted about a reverse osmosis unit however.

The first is the waste that a reverse osmosis system creates. For every five gallons of water pushed through a reverse osmosis unit, normally 4 gallons or so will go to waste. There are various factors which reduce the wastage in a reverse osmosis unit, the main one being the amount of calcium in your tap water. It has been noted that aquarists with soft tap water get a higher volume of usable water to waste ratio than those with hard water.

The second is chlorine. Chlorine is harmful to the membrane which is at the heart of the reverse osmosis unit. For this reason activated carbon chambers are provided for the tap water to pass through before the membrane is reached. These are normally called pre-filters or micro-filters. This pre-filter does require changing based upon the manufacturers recommendations. I recommend that you adhere to these recommendations as replacing the membrane will cost more. In a lot of instances, dependent upon the make and model of reverse osmosis unit purchased it is sometimes more cost effective to purchase a completely new unit.

The third is that the reverse osmosis membrane must constantly remain wet. If the membrane is allowed to dry out then it will become brittle and not function correctly. If this is allowed to happen all you will effectively be doing in sieving the water not purifying it.

Reverse Osmosis devices can be purchased nowadays for very reasonable prices and are available in numerous sizes. Size is normally determined in how much water is processed per hour, therefore a 50gph unit will create 50 gallons of reverse osmosis water per hour when used in optimal conditions.

It is definitely worthwhile investing in a reverse osmosis unit if you have a larger aquarium as the initial water fill and subsequent water changes will require more water, however for aquarists who have smaller aquariums it may not be cost effective to purchase a unit. Fortunately a lot of pet shops are now selling reverse osmosis water so if you have a smaller aquarium then it might actually be cheaper to simply purchase you water from your local fish shop.

As with anything in this hobby the unit does need to be maintained. It does not require a lot of maintenance but the pre-filter on the device does need to be changed at regular intervals. This is normally determined by the manufacturer and I would recommend that you follow their recommendations.

Another thing that I normally do is occasionally test the water from the r/o unit. I test both for nitrate and phosphate to ensure that the unit is running at optimum efficiency.

Another method which aquarists use is to test for total dissolved solids. Meters can be used for this which you can use to test the water produced. You can also purchase inline TDS meters which attach to the reverse osmosis unit. Some reverse osmosis units have these devices fitted.

---

Tags: Aquarium Water, Equipment, marine-aquarium, reverse-osmosis, saltwater-aquarium, Water Quality

Is It All Doom And Gloom? Total Impending Disaster?

Whatever we read in newspapers or watch on TV there seems to be an element of impending disaster somewhere in the natural world. Is it that bad?

First of all it should be remembered that newspapers and elements of TV thrive on ‘doomsday.’ Without bad news there will be a struggle to find a good enough headline. The media, in my opinion anyway, often makes mountains out of not always molehills but hills. It sells, which probably says a lot for all of us!

The major concern with the natural world used to be the cutting down of the world’s rain forests and this remains a high priority. These rain forests have been called the ‘lungs of the earth.’ The issue is even more important now that science has accepted that global warming actually exists. The majority of the public also accept the situation, though there are still those who remain in denial and state it is just a massive scam. The rain forests are capable as I understand it of absorbing very large amounts of greenhouse gas (carbon dioxide) - provided the trees remain standing of course.

But this is a marine hobby website not a discussion forum on rain forests. So fair enough, what about the rain forests of the seas and oceans, the coral reefs. There’s plenty of doom and gloom in this area also. The oceans are acidifying because of absorption of carbon dioxide and also warming up. So if the corals don’t melt because of reducing pH they’ll die because they cannot tolerate the rapid increase in seawater temperature (rapid when compared to the length of time reefs have existed). Also seawater levels are rising and that causes additional problems for the corals. Now all of that’s nirvana for the gloom merchants!

There is a serious problem. There isn’t any denying it, the evidence is available for anyone to see, scientist or not. In some quarters it is said that the reefs are in terminal decline. It has been reported that the rate of decline is 2% each year. Doesn’t seem much but in fact it’s a lot. It has also been reported that around 1/5th of reef life has already disappeared overall, though of course some reefs are in better condition than others.

Reefs in general, though not all of them it depends a lot on location, have been getting into trouble because of us, mankind, for a while quite apart from global warming. This trouble has been due to overfishing, incorrect fishing methods (cyanide for example, which kills lots of creatures besides those targeted - those targeted often die later as well), using dynamite on the reefs to obtain building materials, run-off of silt from the land caused by de-forestation, and run-off of agricultural and industrial pollutants. There’s probably more.

These problems have been bad enough and the reefs now have to also deal with global warming, and they’re not doing well. What a sad and dismal sight it is to see pictures of dead reef areas - just rocks with a few forlorn looking fish around. I, like so many others, have been fascinated when snorkeling over reefs, with all the rainbow colours of the fish, swaying soft corals and the reef builders, the hard corals. How could it have come to such a situation! Sadly, it has.

However, I am neither a pessimist nor an optimist, but a realist. I see these as: optimist, ‘Oh, it’ll be all right, you’ll see,’ pessimist ‘It’s all a disaster, it’s too late, it’s all doomed,’ and a realist ‘Strewth, what a mess, hopefully the scientists might be mistaken though that’s unlikely. What can be done about it?’

There are some hopeful signs.

It appears that the politicians, usually never the ones to move at more than a snail’s pace, have accepted the overall problem (overall = global warming in general) and are looking to do something about it. They need by all accounts to move more quickly, but it has to be accepted that there’s a great deal to consider. The political area is of the utmost importance above anything else. If reasonable agreement can be achieved then the problem can be tackled.

In some of the natural reef areas corals are being grown from ‘frags’ (a frag is a cutting taken from a soft or hard coral). They are grown on extensive trestles beneath the sea. When they are large enough they are transferred to the reef and hopefully in time more corals can be grown from them. If the reef is in danger because of man-made problems, unless those problems are tackled, this action can only be at best a holding operation.

The marine hobby aquarium trade, which to my knowledge has not been accused of causing problems (unlike for example those who collect seahorses for alleged medical purposes or dry them for souvenirs), has tackled some recognized bad practices. Local collectors have been trained to collect in an ethical way and not use cyanide, thus protecting reef life in general and giving caught fish a better chance of continuing to live. Many retailers have voluntarily joined organisations that promote good retail practices, such as importing livestock from recognized sources only and keeping them in appropriate conditions until sold. Imports of livestock for the marine hobby overall are huge and it is obvious that the more sea life is protected the more the reefs will benefit.

What about us marine aquarists? Oh great, here it comes, we must try harder and ‘be good.’ Not at all! There are poor and ineffective aquarists who would be better off giving up the hobby, but they are a small minority.

The marine aquarium hobby has advanced unbelievably over the last decade. Aquariums of all sizes, reef or fish only, are being kept successfully, supported by advanced and reliable equipment. Aquarists have access to huge amounts of information, not only books but through that electronic wonder of the age, the internet. The results of all this can be seen by looking at pictures, a great number of these marine aquariums are truly beautiful.

Keeping a successful aquarium (that is, keeping it healthy for a long period measured in years) is not the major concern. Of course it is very important; a failed aquarium is a mini disaster in itself particularly for the unfortunate livestock. The major concern with the hobby now is production of livestock. It really heartens me when I see how many aquarists are producing home grown corals from ‘frags’ - corals that have not come from the wild but from an aquarium. These are appearing in such numbers now that, if it is not happening already, it will soon have a measurable impact on imports from the wild reefs. There is a further credit to this, and that is that the home grown corals are reputedly less sensitive in an aquarium than those from the wild, which makes sense.

On the same basis, but more difficult to achieve are the fish that are being home bred. These are not appearing in such numbers because of the inherent breeding difficulties. It was a great achievement when clownfish first appeared in dealer’s aquariums having been supplied from home sources. Now many more fish species are appearing as time goes by and one can only salute the patience and knowledge of those aquarists who are involved. How must those aquarists feel as they look upon a tank full of successfully grown saleable fish!

There’s another point about the marine aquarium hobby too. I’ve mused in the past about how big the hobby really is - could it possibly be the biggest hobby in the world? I don’t actually know, but I wouldn’t be surprised if it was. With obvious exceptions, over the globe there are many, many marine aquarists. They keep fish or fish and corals. No matter which, what they have in total is a massive reserve of livestock, both fish and corals.

Already large numbers of corals can be home propagated. As said, the number of fish species that are being home bred is increasing. Perhaps in the future, when the politicians have reached some agreement and global warming and pollution problems have been tackled, marine hobbyists will be able to supply stock for the wild reefs.

How great would that be? Traffic in reverse. Beautiful reefs partially re-built from our aquariums.

---

Tags: aquarium, Coral Reef, marine-aquarium, reef conservation, reef-tank, saltwater-aquarium

The Plenum - Could It Work For You

The word plenum is not a term which the majority of beginners have actually heard of especially when it comes to filtering the aquarium. The plenum however is very similar to that of a deep sand bed however both the creation and design are entirely different.

So what actually is a plenum?

A plenum is not a filtration unit but is actually a space which is located under the substrate and separates the substrate from the bottom of the aquarium.

This space (the plenum) is full of both the water and any organic waste as the water is diffused into it. A plenum is also sometimes referred to as a Jaubert system as Dr Jean Jaubert was the individual who discovered it.

The structure of a plenum is actually very very simple. It is basically a deep layer of substrate which is suspended above the bottom of the aquarium to create a space or a void if you will.

How it works is, although slightly scientific, also relatively simple.

As the water moves slowly through the substrate the nitrifying bacteria in the upper level use up all of the oxygen in the water and convert the ammonia to nitrite and then the nitrite to nitrate. The nitrate which remains is the transported with the water down towards the plenum. As the water reaches the lower levels of the substrate the nitrate is then slowly broken down into nitrogen gas by the denitrifying bacteria which live in the very low oxygen levels of the substrate.

The reason the water moves slowly through the sand is due to the anaerobic action being performed in the lower levels. The anaerobic actions produces heat which heats up the water in the plenum area. This heated water moves up through the substrate which therefore displaces the cooler water above it causing the water to move through the substrate at a very slow rate.

A slow rate of water movement is important in a plenum as it assists in the prevention of a dangerous build up of hydrogen sulphide.

The upper levels in the substrate will become home to various organisms which can either be introduced via the aquarist or are organisms which have relocated from their home in the live rock. These are very important, the same as they are in a deep sand bed. Their job is to keep the upper levels of substrate ‘turned over’ and clean from both detritus and waste.

The above is how a plenum operates but how do you actually make one.

Again this is relatively simple. Not as simple as a deep sand bed as it does require a bit of DIY but simple all the same.

The items listed below are required to make the plenum. This list is not set in stone and can be modified to suit your/the aquariums needs.

Marine safe PVC piping.
Egg crate to make the grid from.
Screening.
Aragonite based sand with a granular size between 1 and 2 mm.
Live Sand.
Silicone.
Tie Wraps.

The recommended minimum required depth of substrate in a plenum is 2 ½ inches when placed on top of the plenum grid therefore you need to ensure that you obtain enough aragonite/live sand to accomplish this.

The first thing you will need to do is actually create the support which the substrate which sit on top of and create the plenum. Personally I find that marine safe PVC pipe is the best for this. These, when laid on their side provide a lot of strength for the substrate held above it.

I would recommend that you cut this piping in lengths of two inches or so and ensure that you have enough of them to support the weight of the substrate above it. Remember that you may also be placing rock on top of the substrate in the aquarium so make enough of them to support this as well. If you are unsure make more than you think you will need.

Once all the support have been kit you will now need to make the grid. The grid is basically there to hold the substrate up and also to prevent any of the substrate from falling down into the plenum area and effectively making it useless.

The easiest way I have found to do this is use eggcrate and cut this to the same dimensions as the inner dimensions of your aquarium. It does need to be noted that the grid needs to be a very tight fit so take your time cutting it. Once cut it can then be attached to the supports. I have found that tie wraps are excellent for this.

The basic structure of the plenum is not in place, however if the substrate was to be placed into the aquarium at this point it would simply fall through the eggcrate into the void. This is where the screen is used.

Cut the screen so that it is slightly larger than the inner dimensions of your aquarium. Once cut carefully place it into the aquarium, fold up the edges and carefully silicone it to the side of the aquarium. You will need to allow the silicone to cure which normally takes about 24 hours but once cured you should have a screen which no substrate will fall through.

Once cured you will be in a position to add the lower level of substrate. Add 1 ½ inches or so of aragonite and give it a really good stir using your finger to remove as many pockets of air as possible. Also be exceptionally careful not to tear the screen otherwise all your hard work will go to waste.

Now that the first layer is in place you will need to cut a second screen to slightly larger than the inner dimension of the tank, and silicone it in place as you did the first screen.

Once the curing process is complete put another 1 ½ inches of the aragonite sand into the aquarium. As with the first layer give it a really good stir with your fingers to remove as many air pockets as possible again being careful not to damage the screen.

Now we are ready for the live sand. Add about 1 inch or so of live sand to the top of the final layer - a screen is not required this time as it does not matter if the live sand mixes with the top layer.

The plenum is now complete and ready for water. When filling with water fill it slowly to avoid creating any air bubbles and mixing all the sand up.

So now we should have a plenum area at the bottom topped with a screen, on top of this screen is some aragonite sand followed by another screen. On top of this screen is some more aragonite sand and then the live sand. All of this is supported via some pvc piping to take the weight and create the plenum space.

In a plenum system it is recommended that little or no water flow be directed across the surface of the substrate. It is also recommended that a protein skimmer be utilised with a plenum as this will assist in the removal of any dissolved organic compounds which are not removed by the plenum.

It is easier to introduce a plenum to a new aquarium rather than the modification of an existing one. If you are interested in introducing a plenum to an existing system you will either have to remove everything from the display aquarium to introduce it or build a plenum in a separate aquarium and attach it to the system using overflows and pumps.

As with the introduction of any filtration device you will need to monitor the water parameters carefully so that you know that the nitrogen cycle is functioning properly.

---

Tags: Aquarium Filter, Aquarium Filtration, Care, Equipment, marine-aquarium, saltwater-aquarium

Next Page »