Construction and Problems – Acrylic Aquariums

I have only ever used glass aquariums, those boxes glued together with silicone. They are immensely strong and long lasting though there can be problems.

The potential problems with a glass aquarium such as a crack or silicone failure (been a bit too hasty with that razor perhaps!) have been dealt with in another text. The requirements for construction have also been covered, such as glass thickness and silicone application.

There is another type of aquarium that is widely used and they are acrylic. It seems only fair to produce a text that deals with the construction and potential problems of those too.

As said I have only used glass aquaria. The only thought in my head for dealing with say a crack (split?) in an acrylic aquarium is to apply heat or a solvent – that could be totally wrong.

My only option was to find somewhere that had good information on acrylics. So onto that wonder of today the internet to search, and after several comparisons the text I sought was found.

Information on how the aquarium should be constructed is given, allowing a judgment to be made before purchase. In addition, there is information on potential problems such as cracking and crazing.

Incidentally, it’s advised that the most common failure with an acrylic aquarium is because the aquarist has placed a metal halide bulb directly above an aquarium strut. Metal halides give out a lot of heat!.

Anyway, here’s the link:

http://www.wetwebmedia.com/acrylicaqrepair.htm

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How To Determine What Aquarium Lighting You Need

When the decision has been made that keeping a marine aquarium is for you the next decisions are what animals you want to keep and what equipment you will need to use.

One of these decisions is what type of lighting you should use above your aquarium.

It is my opinion that realistically there are two options available to guide you towards your decision:

1. Choose lighting which is appropriate for the animals which you hope to keep
2. Choose animals which are suitable for the lighting you have made the decision to purchase

Some people think that this is a strange way to decide however to me it makes perfect sense (but then in my head various things make perfect sense!)

Basically you can go out and purchase some lighting which is relevant to your budget and then design the remainder of your aquarium and livestock purchases around this lighting or you can design your aquarium system including the lighting around the livestock you want to keep.

For example if you have purchased a second hand aquarium system and this aquarium comes with T5/T8 fluorescent lighting and is 18 inches deep from top to bottom then realistically you are looking at either a fish only aquarium or a reef tank with soft corals and perhaps some long polyp stony (LPS) corals.

Another example following this trend would be purchasing a complete aquarium kit from your local fish shop where the lighting is included. In this example metal halide lighting is provided and the aquarium is 24 inches deep from top to bottom. In this example you could again keep a fish only aquarium or a reef tank with either soft corals, long polyp stony (LPS) corals, short polyp stony (SPS) corals or a mixture.

In the second example above if the decision was made to keep a fish only aquarium then the lighting will be overkill as a fish only aquarium does not need intense lighting for the welfare of the aquarium inhabitants. On the same scale if SPS corals were decided upon then other items will also be required to ensure that the aquarium is suitable. Strong water circulation springs to mind.

If lighting is being chosen based upon the aquarium inhabitants which in my opinion is a better way then the following can be used as a guideline:

• Fish Only – T8 Fluorescent Lighting
• Soft Corals – T5/Power Compact Lighting
• Hard Corals – Metal Halide/ LED Lighting

The above is definitely not set in stone as there are other variables which need to be taken into consideration the most important of which is the depth of the aquarium from top to bottom however this is normally only the case when corals are being kept.

If a fish only aquarium is your aquarium of choice then effectively all you need to do is provide lighting so that the fish can see and a dusk/dawn cycle can be created. This allows for the fish to be confident in its home as well as allowing you to see it.

When corals are being kept they require, dependent upon the species of coral strong lighting. Coral use the lighting as an energy source which allows the coral to thrive and grow as long as its other requirements are met for example calcium and water movement to name just a couple.

If you have an aquarium which is 30 inches deep then you will require stronger lighting than if you had an aquarium which is 18 inches deep.

The reason for this is the actual power of the lighting. Lighting power is measured in wattage – the higher the wattage the stronger the lighting will be.

If you had an aquarium which was 18 inches deep then quite probably a 150 watt metal halide would suffice to provide adequate lighting for hard corals to be maintained.

On the other hand if you had an aquarium which was 30 inches deep then a 250 watt unit or perhaps even a 400 watt unit would suffice to provide adequate lighting for hard corals to be maintained.

Wattage power in lighting is important as we want to ensure that the light unit has enough power to punch the light right to the bottom of the aquarium without losing colour. The deeper the light has to penetrate into water the quicker the colour from the spectrum is lost.

It is feasible that hard corals could be maintained in an aquarium that was 30 inches deep with a 150 watt metal halide unit however the corals would have to be placed in the top third of the aquarium.

Aquarium lighting is quite a complex subject especially when it comes to discussing the colour spectrum therefore I am not going to go into this in this post. Effectively at this point you want to try and push as much of the light right to the bottom of the aquarium.

One thing you do not want to do is allow light to not go into the aquarium. By this I mean allowing the light to go over the top of the aquarium into the surrounding room or allow it to be ineffective light due to a badly designed reflector.

Reflectors are used to direct as much light as possible from the bulb down into the aquarium. There are some designs which due to their design reflect a lot of the light back into the bulb itself rather than down into the aquarium which therefore means wasted light. A good reflector will reflect light around the bulb and down into the aquarium. The majority of good quality aquarium lighting units nowadays come with good quality reflectors but it is something you should be aware of.

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DIY Metal Halide Lighting

Do It Yourself (DIY) with a project of any kind is not for everybody. However, there are large numbers of people who do complete various projects successfully, and there is a lot of satisfaction to be had never mind the financial saving. Often the only requirement to start a project is a guide or laid out plan of action.

Marine aquarists have a lot of scope to demonstrate their skills with DIY. For example, some construct their own filters, protein skimmers, lighting hoods and aquarium stands etc. Some make the aquarium itself.

The lighting for a reef aquarium is very important for the health of the corals. Failure to provide proper lighting, both intensity and spectrum, is the road to failure. Different coral groups require different intensities of light. Where the aquarist requires intense light then metal halide systems are often chosen.

The aquarist could consider DIY for the metal halide system. There isn’t a requirement to be a qualified tradesman, just a need for a basic capability and the care to complete the job. With electrical items of course the aquarist needs to be aware that electricity and misuse are dangerous. Having said that, there isn’t any reason why a DIY project cannot be completed in this area also. However, if there is doubt, don’t attempt it. If the job is in progress and there is doubt, obtain qualified advice.

As already said, all the DIY aquarist really needs is the guideline and advice to follow. So below is a link which provides that. Using a search engine on the internet will no doubt find more sources.

There is another way for a DIY project to commence, though this one is even easier because the parts don’t have to be searched for. This method is called ‘retrofit’ and there are kits available that provide all the parts and the instructions for construction. They are very straightforward.

Before the aquarist starts it is necessary to research the intensity of lighting that is required, that is the power (watts shown by a ‘W’) of the bulb(s). This intensity depends on the type of corals to be kept and also the depth of the aquarium. This applies whether the lighting is a DIY project, a ‘retrofit’ kit, or ‘off the shelf.’

http://www.personal.psu.edu/sbj4/aquarium/mh/mhlighting.html

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Will LED Lighting Ever Replace Metal Halide?

Whatever type of marine system is kept lighting is important. With a fish only aquarium the fish need a day cycle and of course need to see where they are going. It’s also good that the aquarist can see the fish! With reef systems the lighting is also important for the same reasons as far as the fish are concerned and more important for the corals.

Before looking at LED’s (light emitting diodes) it’s necessary to see what the LED’s need to be able to do to compete with metal halides.

Metal halide lighting systems are used exclusively for reef aquariums (if used on a fish only system then electricity is being wasted). Sometimes the aquarist is able to use fluorescent T5 tubes, but this depends on the depth of the aquarium – can the light penetrate deep enough?

In this case it is assumed that metal halide bulb(s) are needed.

Metal halide is basically a bulb that uses a filament, the bulb being inside a reflector. The bulbs are rated in watts and there is a range available, the most usual ones being from 150W up to 400W. The wattage is chosen according to the depth of the aquarium. The more watts, the more expensive it will be to run because of electricity usage.

The length of aquarium that a single bulb can light with usual width aquariums is 3ft (circa 91.5cm). This is a guideline not a rule. For a 6ft aquarium two bulbs would therefore be required, doubling the running cost.

The bulbs also need to meet another demand of the corals in addition to intensity and that is spectrum. A lot of the commonly kept corals contain zooxanthellae within the flesh. Zooxanthellae are single celled algae that are essential to the well being of the coral. In order to function (photosynthesize) they need light of the correct wavelength and fortunately metal halide bulbs can achieve this light output. In fact, there is a choice of outputs within limits.

Metal halide bulbs need to be changed regularly according to the manufacturer’s recommendations or the intensity could diminish and/or the spectrum shift.

To make the reef more natural (a goal which is being achieved more and more), many if not most aquarists incorporate one or two additional fluorescent tubes which are usually in the blue spectrum. This assists the delivery of the correct light to the corals and additionally, with the use of electric timers, gives a ‘dawn and dusk’ effect. That is, the blue fluorescent tubes switch on around half an hour before the metal halide, and switch off around half an hour after the metal halide. This avoids sudden bright light or sudden darkness, both of which are undesirable.

Are there any downsides to metal halides? Yes, there are two. The first one is running cost because the bulbs are electricity hungry. Consider a bank of two 400W bulbs ‘that’s not far away from a kilowatt per hour. If the lights are on between 8 and 11 hours a day’..well, you get the idea.

The second downside concerns the aquarium livestock. Stability in any marine system is very important and should be maintained as far as possible. Metal halide bulbs run very hot, and radiate directly into the aquarium as obviously they must. This heats the seawater and it is possible for the seawater temperature to rise unacceptably. If this is the case then the aquarist needs to purchase a chiller (seawater cooler) which is not particularly cheap to purchase or cheap to run. It may be possible for the aquarist to run surface air fans for cooling and many aquarists do this. In this case ideally the seawater temperature and/or time need to be linked into the fan system or, if the seawater cools down because the metal halide has turned off, it may be overcooled and the heaters will switch on for longer periods using more electricity.

So then, what about LED’s? These type lights are used widely nowadays for decorative and commercial purposes as well as more recently being of use to marine aquarists. Aquarists could already be making use of low-powered LED lighting in the form of blue lights that switch on after all the other lights have switched off. They simulate moonlight and give a really good effect, beams of flickering weak light in the seawater. These are not a competitor to metal halides of course.

Fairly recently more powerful LED’s have appeared. They are similar to metal halides in two ways – they come in a canopy and use electricity.

The makers of some canopies have claimed that the light output (the combined output of all the LED’s in the canopy) is equal to X watts of a metal halide, this being 150W, 250W or whatever – the more LED’s the more power. I am not a lighting expert but have noted some argument over this claim. However, contributors to the argument seem to agree that the output is close and is increasing as technology advances. The important point is that there are reef systems that are thriving under LED lighting.

There is another LED system available that is not a standard canopy. These resemble to an extent a fluorescent tube in shape, and can be purchased in different lengths and, again to an extent, different spectrum outputs. So, as with fluorescent tubes, different units can be combined over the aquarium.

LED’s do not need to be changed as regularly as metal halides, in fact they could last 20000 hours. That’s a long period of aquarium lighting, just divide it by the amount of time the aquarium lights are on each day. So there isn’t a requirement to spend money on new bulbs once a year or so.

The heat from LED’s in canopies is not directed into the aquarium as the canopies usually contain a fan to channel the heat away. In warm areas this will add to the work that air conditioning needs to do. Most aquarists will not need to purchase a chiller or employ fans to cool the seawater, which should remain more stable in temperature. The LED’s that are a little reminiscent of fluorescent tubes do not have fans – to be honest I am not sure of the heat output effect but would assume that it will not be great as each ‘tube’ often has less than ten LED’s present.

There isn’t a requirement for additional fluorescent tubes, so the aquarist misses that expense and the need to change the tubes once a year or less. This is because the LED’s incorporate both white and blue LED’s and, in the canopies at least, these usually can be timed on and off according to the aquarist’s wishes. In fact, in the more expensive canopies, the effect of a cloud rolling across the sky can be timed in.

Obtaining a metal halide system costs less than an equivalent LED canopy, and obtaining a fluorescent tube costs less than an LED ‘tube’. That is the problem at the moment with LED systems, the initial cost.

However, when the ongoing cost of a metal halide is considered against the same for LED’s, the LED’s show a considerable saving. In addition, the LED’s do not heat the seawater (at least not to the same extent) and permit the aquarist to maintain temperature stability more cheaply.

Importantly, LED’s are not so electricity hungry.

LED technology continues to move forward and it seems clear that if the current LED systems can be successful then ones in the future will be and better. It is now necessary more than in earlier days to be careful with electricity costs and it is doubtful if this is going to change significantly.

My own guess is that the future for LED’s is assured and the metal halide will begin to fade away before too long. The price of LED systems does need to come down though before LED’s become the usual lighting system considered by most reef aquarists.

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Can Natural Aquarium Lighting Work?

The wild coral reefs sit under the sun and do well. Everything is correct – spectrum, intensity, photoperiod and the dawn/dusk sequence. Could the aquarist make use of Nature’s original?

For aquariums that contain corals the importance of aquarium lighting runs a close second to seawater quality, so it would seem reasonable to consider using the natural stuff. There are potential problems however.

The first consideration is sunlight and its availability. The skies over wild reefs are often blue but not always, clouds pass over and sometimes storms. Therefore continuous sunshine is not a necessity. However, for most of us in temperate areas the amount of cloud we experience is much more and I wonder how the zooxanthellae (algae within corals) will fare. They need the correct light to prosper and it is probable that the corals would have problems.

There are aquarists in blue sky areas where cloud cover is not so prevalent, and maybe the sunshine periods are not too far off those on wild reefs. So using natural light is more of a proposition. How could the sunshine be directed to the aquarium from the top? Allowing the sun to shine on the front glass of the aquarium could produce excessive algae growth there, thus spoiling the aquarist’s view and causing excessive cleaning of the glass. If the seawater is of high quality with little or no nitrate and phosphate, as it should be, algae growth within the aquarium shouldn’t be a problem, but it always surprises me that the stuff does appear quite clearly on viewing glasses nevertheless. Having said all that, if there is a fairly substantial nitrate and/or phosphate presence then algae could well proliferate much to the aquarist’s annoyance – the word sunlight could well turn into sunblight.

The answer could be to put the aquarium in a room below a low roof where a roof window of suitable proportions has been provided. This would allow the sunlight to slowly hit the top of the aquarium, reach full intensity, and then slowly reduce again. The risk of the seawater overheating would also be much reduced.

I am only aware of two aquarists that have used natural sunlight, and in both cases am not aware of the complete result.

In the first instance the aquarist did in fact have a window in the roof more or less as described and the corals did well for a while. Unfortunately, the area of the world where the aquarist lived meant that the sun dipped towards the horizon as the seasons changed and the sunlight became too weak or missed the aquarium completely. I feel sure the aquarist would have known the sun would do this but he must have miscalculated. What was done about it I don’t know – I’m sure putting the aquarium on wheels wasn’t an option!

In the second case the aquarium was located in a conservatory. There were too major problems, I know that one was fixed but don’t know about the other.

Clearly, in a conservatory with its glass roof and sides sunlight would have unrestricted access. Conservatories when bathed in sunlight can become very warm – this is one of the attractions of them. Unfortunately, this warmth caused problems with seawater temperature stability, usually climbing too high. The aquarist obtained a cooler (chiller) and as far as I am aware this cured the problem. The second problem was as mentioned earlier – algae. This algae not only caused very regular cleaning of the viewing glasses to be required, but caused excessive algae growth in the aquarium itself causing the aquarist to appeal for assistance (generally, not to me personally). I noted the nitrate level was quite high (if I remember correctly it was about 30ppm) but there wasn’t a mention of phosphate so that could have been anything. The aquarist was advised to reduce the nitrate level and reduce and control the sunlight (how?) but didn’t respond further. Perhaps the aquarium was re-located.

A keen advanced aquarist experimenting is great and this is how progress is achieved, and is to be applauded. However, with the hobby in the position it is today the usual path with lighting is better for most.

The aquarist can have lighting exactly suited to his/her needs relevant to the livestock being kept. That lighting can be closely controlled by the use of electric timers and an acceptable dawn/dusk sequence introduced, and the photoperiod adjusted according to need. For the great majority of us electric lighting is the answer.

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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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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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