Re-iterating The Importance Of Aquarium Water Movement

Seawater that is not moving or sluggish could be close to ‘dead’. In that condition it is not going to carry out the important functions that are necessary.

I remember once reading in a marine hobby book that the aquarist needn’t worry too much about fish and seawater movement, the fish swimming about would create enough movement. Er, sorry, but wrong! Admittedly the book was read many, many years ago and the author would be correct in one respect - as the fish swam along the seawater would move past them. This was written in the days well before corals had made an appearance, but nevertheless we now know better, a fish only aquarium would not be healthy without sufficient seawater movement.

So why is seawater movement so important? The movement supports important functions without which there would be problems.

The seawater needs to move fairly vigorously, not a maelstrom but significant. The movement should not be linear but random and chaotic.

In a fish only system the guideline is around 10 times the net gallonage of the display aquarium. Any gallonage in a sump is ignored. The first thing achieved is that oxygen in the seawater is plentiful. Oxygen is taken in at air/water interfaces, and the biggest one of these is the seawater surface in the display aquarium. Seawater is constantly moving to the surface and away again hopefully saturated with oxygen, which is then carried to all parts of the aquarium system including the sump if used. It can be seen how important sufficient oxygen intake is when it is considered that seawater in a marine aquarium with a high oxygen content is often between 6 and 8 ppm (parts per million). Not exactly a high ratio! In a heavily stocked fish only aquarium the demand for oxygen by the fish is high. Obviously a drop in the oxygen supply would cause fairly rapid symptoms such as fish close to the seawater surface where the oxygen content would be higher. The second advantage to fish is that the seawater movement prevents an ‘envelope’ of static seawater from developing around the fish, which, as I understand it, could interfere with the fish’s osmotic requirements. The movement, on a much more secondary level, makes food move about attracting the fish and inviting them to chase it down.

In a soft coral reef aquarium, fish or no fish, the guideline for seawater movement is the same as in the fish only system which is about 10 times the gallonage of the display aquarium per hour. The seawater is oxygenated in the same way, and the movement brings this oxygen to all parts of the system and around the corals. Branched soft corals can be seen responding to the movement as a field of corn does to wind, and the corals are likely to extend their polyps further than in a system with poor circulation. Some corals would not exhibit their polyps at all. The seawater movement helps the corals clear mucus and debris from their surfaces and also brings food within reach.

Generally SPS (soft coral stony) hard corals require more movement than the soft variety. The guideline is around 20 times the net gallonage of the display aquarium. This seawater movement gives the same advantages to the hard corals as it does to the soft types - it causes better polyp extension, clears the surface of debris and mucus, and brings food. The reason more vigorous movement is required is because of the area the corals inhabit on the reef.

When an aquarist is considering purchasing a coral, consideration should be given to the area on the wild reef the coral would normally inhabit. This will permit better placing of the coral on the captive reef in relation to light and seawater movement. It is quite possible for an aquarist with a hard coral reef system where seawater movement is around 20+ times per hour to keep soft corals (subject to compatibility) - the guidelines are not that rigorous. The seawater movement lower down is often more subdued and suitable for soft corals.

When all is considered, there aren’t that many demands that have to be met for a healthy marine aquarium. Top of the list is seawater quality. This includes oxygen content which means sufficient and appropriate seawater movement is required.

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Tags: aquarium, Aquarium Water, home-aquarium, marine-aquarium, Water Movement, Water Quality

You Need To Have Enough Filtration In Your Aquarium

A successful marine aquarium is a wonderful sight. It doesn’t matter whether it is a fish only, coral only, or fish and coral system, there are certain items that need to be up to the job.

The first essential requirement is seawater quality, closely followed - at least in a coral only or coral and fish aquarium - by lighting. It is the need for seawater quality that makes filtration so important.

There are basically two types of aquarium filtration, excluding protein skimming which is often counted as such. The first is mechanical/chemical filtration and the second biological.

Mechanical filtration is where media removes sediment from the seawater by trapping it in suitable media. This is often done by using a canister filter which needs to be cleaned regularly and the media changed if it is showing signs of wear or failure. Mechanical filtration is not an absolute requirement and many aquarists do not use it. It is usually only necessary when there is a fair amount of sediment floating around in the seawater. Before employing a mechanical filter, it is best for the aquarist to ascertain why there is sediment and try to correct the problem.

Chemical filtration is also often done by using a canister filter and can be in conjunction with a mechanical stage - if so the mechanical stage normally comes first. Chemical filtration covers activated carbon, phosphate removing media etc. Again it is not mandatory to use this type of filtration, though some aquarists use activated carbon to supplement the protein skimmer and others run an anti-phosphate media continuously (phosphate is a nuisance algae nutrient and is mainly introduced with food).

By far the most important filtration is biological, and this applies to any type of system. The filtration carries out the ‘Nitrogen Cycle’, which is something all aquarists should clearly understand. Livestock introduce a toxin into the seawater, namely ammonia. This toxin is deadly to life forms in low concentrations but fortunately Nature has the solution. The biological media provides a home for bacteria in their millions, and the first group of bacteria convert the toxic ammonia into nitrite. Unfortunately nitrite is also a toxin and very nearly as bad as ammonia. However, a second group of bacteria convert the nitrite into nitrate, which, though problematical in a high enough concentration, is not generally harmful. If the Nitrogen Cycle is able to run the full course the nitrate is converted to gas which escapes the seawater.

There are one or two points that need to be remembered about the bacteria that provide this essential service. The first is that the bacteria that convert ammonia and nitrite are oxygen hungry, and to ensure their proper function it is necessary to provide seawater rich in oxygen by having adequate seawater circulation and air/water interfaces.

The bacteria that are able to convert nitrate to gas are not the same. They would use oxygen if it was available, but if it is not they take the required oxygen from the nitrate, thus breaking it down. Therefore the bacteria need to be in a very low or no oxygen environment to ensure that the required function is performed.

If for example a canister filter is being used for biological filtration the media is constantly exposed to oxygen. Therefore the breakdown of ammonia and nitrite will occur but nitrate conversion will not. Nitrate will remain in the seawater and will increase unless other adequate measures are taken.

If the biological filtration is by good quality live rock, then the full Nitrogen Cycle, that is ammonia-nitrite-nitrate-gas, should occur. This is because the oxygen loving bacteria accumulate near to the surfaces of the rock, and the bacterial nitrate converters are deep inside where oxygen is depleted.

Having considered all of this, it is clear that there needs to be adequate filtration material to accomplish the biological task. For example, a fish only system can employ live rock. Fish are producers of ammonia, much more so than corals, and an adequate amount of good quality live rock is needed to process the toxins. The live rock amount would need to be increased if the fish numbers were high as obviously there would be more toxins produced. As a general guideline 1½lbs of good live rock is considered necessary for each gallon in the complete system. So if there is a sump, count that in. There is a problem with the ‘weight system’ as live rock can be of differing weights, therefore when purchasing seek advice.

Similarly, when using a canister filter (or similar) for bio-filtration it is important to ensure two things - first that the canister can contain sufficient bio-media for the intended load and second that the flow rate through the filter is adequate. Manufacturers will advise the recommended aquarium size for canister filters, and media manufacturers will advise the suggested bio-loads.

Mechanical/chemical filtration is not so essential, so reading the media manufacturer’s recommendations is sufficient, if these types of filtration are required at all.

Stocking a marine aquarium without an adequate amount of bio-filtration will soon become obvious to the aquarist - sickly livestock and quite likely losses. Inadequate bio-filtration is likely to hit fish systems the most as they produce most toxin with their life functions. However, all systems require adequate bio-filtration, Nature’s free and essential service.

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Tags: Aquarium Filter, Aquarium Filtration, Aquarium Lighting, Care, Equipment, Water Quality

When To Replace Your Aquarium Lights

There is only one thing that is a little more important than lighting with a marine aquarium and that is water quality. Lighting is only really important though when light demanding life is kept, such as in a reef aquarium.

If the system is fish only then lighting is important but nowhere near as much. Fish need to be able to see and the aquarist wishes to see them. That’s it. Of course, it is still desirable to have a dawn/dusk effect using at least two fluorescents, usually blue and white, with electric timers so that something approximating the increase and decrease of light at the beginning and end of the day can be provided. When should the fluorescent tubes be changed? If a tube is seen to be flickering then it needs changing. If the aquarist thinks the light has diminished it probably has, so get a replacement tube. If the ends of the tube(s) are blackened then it is getting old and could do with changing.

The reef system is a different matter. Here, lighting is usually fluorescent tubes, metal halide or a mixture of the two. As corals are being kept, be they soft or hard types, or a mixture, the lighting needs to provide the correct spectrum and intensity. When the lights are new they will do, but as time progresses the lights reduce in intensity and the spectrum can shift, both undesirable. The only way to correct these problems is to renew the light source.

When to renew is the subject of argument among experienced aquarists and particularly among very keen ones. Some argue that fluorescents should be changed as frequently as every 3 months and metal halide bulbs every 9 months. However, the guidelines for changing tubes and bulbs are more generous than that.

In the case of fluorescent tubes the point when flickering and blackened ends arises as previously mentioned should never be reached. The tubes should be changed well before that. The guideline is 12 months maximum from the date of first use. There isn’t a problem in changing the tubes more regularly than this of course and will not do any harm at all. I change my fluorescent tube array every 9 months.

Metal halide bulbs could be changed after a maximum 24 months from date of first use. This seems a long period and many aquarists, to be on the safe side, change more frequently. I do not use metal halide, but if I did I would probably change every 12 months. The expense is not too high. Changing the bulbs varies with different aquarists, some change at either 9, 12, 18 or 24 months! Just be safe by changing regularly at a shorter interval than recommended.

The recommendations for the expected life of a bulb, particularly metal halide, are usually available from the manufacturer. This is often given in hours so that varying lighting ‘time on’ periods can be accommodated. Once the recommended hours are known it is a simple matter to divide this by the daily running time so that life expectancy can be seen.

All aspects of marine aquarium husbandry require attention from time to time. It is essential to pay heed to one of the major ones, lighting. The use of a note book is recommended to remind the aquarist when a lighting change is due, and the notebook is useful for many other memory aids.

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Tags: Aquarium Lighting, Aquarium Maintenance, Care, Equipment, home-aquarium, Water Quality

Can Decorative Sand Be Used For Filtration

This is a very good question which I was asked recently via email and I thought that I would detail it here for others to read and hopefully benefit from.

A lot of aquarists decide to put a small amount of decorative sand in the bottom of the aquarium to make it look more natural. This sand is normally something like coral sand, live sand etc.

Normally a small scattering is put in the aquarium - just enough to cover the bottom of the aquarium. At first the aquarium does look very natural however before long the sand starts to get clogged up with detritus, uneaten food and unless the aquarist cleans it then it can start to look very dirty.

Whilst looking into possible methods to keep it clean the aquarist may stumble upon a term called deep sand beds. After a small amount of research the aquarist may decide to ‘give it a go’ and after purchasing more of the sand installs it into the aquarium and believes that he/she now has a deep sand bed.

Wrong I am afraid and this is a deep sand bed which is probably destined to fail.

The reason for this is that the sand used in a deep sand bed has to have sand particles which are within a given size range. This is so that the animals which live in the sand are able to move the sand around. This is a term which is called turning the sand bed over. The animals will not magically appear. Some will migrate from the live rock if this is used in the aquarium, however the majority will need to be introduced by the aquarist. Not just once either the bed will need to be topped up from time to time. Once the bed has animals in there they then need feeding so that they can reproduce and increase the diversity in the sand bed. For this they need to be fed by placing some food directly onto the sand bed alternating where the food is placed. Other animals can also be purchased and introduced to the aquarium to assist in the cleaning up of the sand bed. These can be hermits, starfish etc but they have to be ones which will survive in a sand bed.

The other thing that is required is the actual depth of the sand bed. The sand bed needs to be a minimum of four inches in depth. Having a deep sand bed of at least this depth will create a bed which is low in oxygen at the bottom. When this happens this allows for the relevant bacteria to live which will assist in the filtration.

There are a large amount of aquarium stores now that sell sand which is designed for use in the the creation of a deep sand bed. There is a variety of colours to choose from however personally I prefer the natural ’sand’ looking colour!

A deep sand bed is a very powerful tool for filtration and is often underestimated. Combine a deep sand bed with live rock and you have an aquarium filtration system with a large amount of power. As long as it is properly setup and properly cared for.

In answer to the question - yes decorative sand can be used for filtration as long as the fundamentals of deep sand beds are understood.

Below are links to two articles we recently wrote on this subject:

The Deep Sand Bed - One Of The Most Effective Filtration Methods

Deep Sand Bed Construction

Feeding a Deep Sand Bed

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Tags: Aquarium Filter, Aquarium Filtration, deep-sand-bed, live-rock, plenum, Water Quality

Why Do Algae Blooms Occur In The Home Aquarium

Algae blooms can occur at any point in a home aquariums life but normally algae blooms occur during the start of the aquariums life.

When the home aquarium is first started everything is new. All the equipment, the sand, the rocks, the water etc are new. The aquarium needs time to settle in.

A good example of this is the sand. Quite often near the start the sand can become covered in what looks like a dusty brown covering. Quite often this is due to the silicates in the sand. When the silicates are all used up the algae simple disappears - quite often overnight.

As already said though an algae bloom can happen at any time especially if the water quality is not maintained at optimum quality. A couple of nutrients which can cause problematic algae to occur is nitrate and phosphate. The trouble in this instance is that the algae is using up the nitrate and the phosphate in the water therefore when the aquarists checks the parameters they show quite low, however behind the scenes there is a potential problem.

Another area is not looking after the equipment correctly. Two areas which spring to mind are the protein skimmer and the aquarium lighting.

If the protein skimmer is not maintained correctly then not all of the dissolved organic substances etc will be removed from the water and will be processed by the aquarium filtration and will therefore create nitrate etc which otherwise you would not have had.

If the light bulbs are not changed in accordance with manufacturers recommendations then the lighting will be below ‘par’ and could be producing lighting which is at the wrong end of the spectrum and algae which likes this type of colour could start to thrive.

There is another aspect which springs to mind and that is water flow. If there is not enough water flow in the aquarium or even in areas of the aquarium then algae can start to grow in these areas, cover the rocks perhaps even the corals.

The trick is to ensure that you maintain the aquarium correctly - perform all the required care and maintenance and attempt to keep the water at as high a quality as possible. Doing this however does not guarantee that you will not get any algae growing however it should reduce the likelihood of one occurring.

All algae have a food source. If an algae outbreak does occur the best thing to do in my opinion is identify the type of algae it is, identify what this type of algae feeds upon and remove its food source. Once the food source has been removed the algae will start to disappear.

There are also a lot of ‘quick fixes’ on the marketplace at present. Ones which promise to remove algae ‘magically’. Whilst I am sure that some of these do actually work are they just masking the problem and as soon as you stop using it the problem will re-occur. I personally think so. In my opinion the best thing to do is look after the aquarium correctly.

A lot of aquarists give up this hobby and the majority do so due to algae outbreaks. When thinking about setting up the aquarium they picture and aquarium which is always clean. They soon find out that this is not the case and go from outbreak to outbreak and eventually they get fed up and give up.

The internet is a huge source of information and fellow aquarists are always willing to help other aquarists. If you do experience an outbreak then the first thing to do is check all your water parameters. If there are any areas of concern then these should be rectified and hopefully the algae will go away. If not then the next thing to do is check the equipment to ensure that it is all working correctly and if required to be replaced has been.

If after doing this the algae is still apparent then pop to your local fish shop, speak to a friendly aquarist and ask their opinion. You will find that the majority of people are prepared to help out. If you do struggle then as said the internet is a source of great information. In this instance probably a forum or social community would be your best bet as you will be able to upload a picture of the algae where other hobbyists will be able to identify it and inform you of its food source. From this information you will be able to remove the food source from the aquarium and the algae should go away.

Of course you may get another outbreak. There are some aquarists who never have one - my dad John is one, he has never had an algae outbreak in his aquarium but then I have never seen another aquarium with water quality at the level he keeps his maintained at. Makes me jealous every time I see it!

The good thing about algae outbreaks in that each time you get one you learn something else about this hobby. This is now information that you can use to assist others if they get one and if you get another one then you will learn again.

As we always say - ‘in this hobby you never stop learning’.

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Tags: Algae, Aquarium Maintenance, Care, home-aquarium, marine-aquarium, Problems, Water Quality

Water Changes - Why Are They Performed

Part of all aquarists maintenance routine should be performing a water change on the aquarium. Water changes are not just limited to saltwater aquarium - all home aquariums have a requirement for their water to be changed.

I was doing my water change today as part of my weekly maintenance regime and I thought to myself ‘how many people change the water without actually knowing why they are doing it…’

This article is aimed at owners of saltwater aquariums as there are slight differences between saltwater aquariums and other home aquariums - one of which is salt of course!

The recommended amount of water to be changed is 10% per week however this is not a figure which is set in stone as more may be changed if there are problems with the aquarium and less may be changed for various other reasons.

Due to the percentage water change this does mean that some people will be changing a small amount of water and others will be changing a lot more. Personally I have an aquarium where I am able to make up enough reverse osmosis water to perform the change. My aquarium is 100 gallons so 10 gallons is relatively easy to produce as my reverse osmosis unit is quite quick.

Other people decide to make up a large batch of reverse osmosis water and keep it for use until the container runs dry.

It’s whatever works best for you really.

If you look at the back of the box/container which the dry salt mix comes in you will see that it is made up of many things. This is one of the reasons why we change water.

The animals which we keep in the aquarium, especially corals, use some of what is in the water. Each of them has a different demand and slowly but surely the amount in the water is slowly reduced. When a water change is performed this element is added back to the water so effectively the element(s) being used are topped up which the livestock can then use.

One of these such elements is calcium. A lot of life in aquariums require calcium. When a water change is performed calcium is added back into the aquarium. For some aquarists this will be enough to maintain the calcium at the required level however for others they may need to use alternative methods to top up the calcium levels.

The replacement of required elements is a very important reason to change the water in the home aquarium however it is not the only reason.

Another reason we change water is that we are able to remove dissolved organic compounds from the aquarium before the filtration has had time to break them down. The protein skimmer attached to the aquarium can only process the water which flows through it and not all of the water in the aquarium will do so. It is recommended that when you perform a water change that you clean the rockwork as well. By blowing the detritus etc on the rock work in the water column this can be removed at the same time as the water. When a water change is performed some of the dissolved organic compounds are also removed and the water which replaces it is nice and clean.

If a sand bed is used for decorative purposes only i.e. it is not a deep sand bed or a plenum then the time when a water change is being performed is a perfect time for cleaning the sand. Stirring it is fine as all the detritus etc will flow up into the water column and can be siphoned out with the water.

When water is removed from the aquarium any nutrients in the aquarium are also removed. One of these is the dreaded nitrate. All aquarists aim for readings of zero when it comes to nitrate however water changes can be used to control nitrate. For example if you have 10ppm for nitrate in the aquarium and replace 10% of the water then your new reading should be 9ppm. Over time and with careful management this nitrate reading can be reduced further. Another nutrient which can be controlled/managed via water changes is phosphate.

Therefore effectively the main reasons we perform water changes is to add essential elements back into the water which have been used by corals, fish etc and also to remove nutrients, detritus etc from the water whereas if left they could be broken down by the filtration and become problematic.

I personally belive that water changes are one of the first things to be skipped when aquarists become lazy with the aquarium care and maintenance. At the end of the day we perform water changes so that we can attempt to achieve what all aquarists attempt to get - excellent water quality. If water changes were not performed then the fish, corals etc which live in this confined environment will be living in an environment which is not suitable for them.

Would you like to live in an environment which was polluted, full of nutrients and over time would make you poorly? I know I wouldn’t - so why make your livestock.

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Tags: Aquarium Maintenance, Aquarium Water, Care, home-aquarium, Water Quality, water-change

Look After Your Membrane

High quality seawater has been said many times to be the number one requisite for success with a marine aquarium of whatever type. It doesn’t matter if the aquarium is fish only or reef, seawater quality counts, though it has to be said it usually counts more with a reef.

The aquarist spends time making sure the seawater quality is high by doing tests for various parameters and carrying out routine seawater changes to reduce pollutants, help replenish trace elements and generally freshen things up.

What about the other end of the operation? When the seawater is made up some aquarists use tap water. Others use reverse osmosis (RO) water, which is tap water that has been passed through an RO filter unit. Using RO water is highly recommended. In this way a large amount of the pollutants that are in tap water - and these vary from area to area - are removed. RO water is generally 95 to 98% pure.

The pollutants are removed by forcing tap water, using mains pressure, through a membrane. This membrane will only permit (nearly) pure water to pass. The rest is allowed to run to waste, unless the aquarist collects it for gardening purposes or whatever. The ratio of purified water to waste water is around 1 to 4 or 5.

The advantage of using an RO filter can be lost. RO filters are pretty simple and require little maintenance but nevertheless occasional attention must be given to ensure efficiency is maintained.

The heart of the RO filter is the membrane. This is where the good is separated from the bad, so it follows that failure here will negate the operation. So protection of the membrane is the order of the day.

There are two types of protection required. The first and probably most important is protection against chlorine. If chlorine has access to the membrane, the membrane will be damaged and will not remain properly functional. Water purity will fall and it is likely that a replacement membrane will be required. (The membrane is the expensive part of the RO filter and it may be worthwhile obtaining a complete new unit.) Protection against chlorine is achieved by using a carbon unit, which is supplied as part of the RO filter. During use there is nothing that needs to be done to the carbon unit. However, when the RO filter is first purchased a note should be made of the manufacturer’s recommendations as to how long the carbon unit will last. This is usually given in gallons and the number will be high. In the home situation the carbon unit will last a long time, so it is worthwhile either logging down the amount of each usage in gallons, or multiplying up the known weekly usage. The aquarist will of course know the amount required for seawater make-ups for routine changes, and also the amount required for evaporation top-ups. The two added together is the weekly usage though it might vary a little. If the manufacturer’s recommendation for gallons is divided by the weekly usage, the answer is the life of the carbon unit in weeks. Once the end of this period is being approached a new carbon unit should be ordered.

The second protection needed is against detritus. There is detritus in tap water though hopefully there isn’t much. Many manufacturers recommend cleaning the detritus filter at intervals of X gallons, and this is all that is normally needed. Looked after, the detritus filter should last the life of the RO unit overall.

Though some more expensive RO filters use more sophisticated methods, an occasional check of the quality of the RO water being produced is worthwhile. A check for nitrate and phosphate is usually sufficient. The test kits should be suitable for fresh water of course.

Maintaining the efficiency of the RO filter helps the aquarist achieve from the start the conditions required for success.

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Tags: Aquarium Maintenance, Aquarium Water, Care, Equipment, reverse-osmosis, Water Quality

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