The Future

 

Wow, now that’s a big title, so it had better be reduced straightaway! What ‘future’? It’s got to be marine aquariums of course, but excluding the gloom concerning the wild reefs.

In some areas that could be discussed the future is fairly apparent if only generally. For example, the car is going in one or two directions (or more) because of the increasing cost of fuel: they’ll be hydrogen or electrically powered, probably hybrid as well. This will take some time of course, as support structures are required for the new fuels (particularly hydrogen presumably) and perhaps more time needs to pass to allow the cost of conventional fuels to rise further increasing the pressure for change.

It’s more difficult with marine aquariums, basically a glass or acrylic box with seawater and livestock. It depends mainly on three areas for success: first, the marine aquarist needs to be reasonably basically knowledgeable, second the aquarium needs the correct support equipment and third Mother Nature needs to be happy (high quality seawater and habitat for the living inmates). Looking to the future on that basis doesn’t really turn up much as aquarists will probably remain the same mix as now. Glass and acrylic are, well, glass and acrylic (perhaps production methods could be improved but that’s not what’s being looked at). The support equipment such as heaters, skimmers, pumps etc could show a little more promise. Heaters generate heat with wattage and this is unlikely to change. Pumps could perhaps become more efficient in the use of energy and maybe in the way they move seawater, although there are pumps available now that give choices. Lighting seems to show the highest ‘future rating’ at least at the moment.

There are two types of lighting mainly in use, fluorescent tubes and metal halides. The former are used on fish only systems and also some reef systems. The latter are really for reef aquariums. Fluorescent lighting is reasonably cheap to buy and easy to install and a big plus is that running costs are not particularly high. Metal halides are also reasonably easy to install but the running costs are higher. Metal halides use quite a lot of electricity with bulbs being rated quite commonly at 250 and 400 watts, there are others more powerful. The light they emit is intense and the spectrum tailored. There isn’t any doubt that they are successful in adequately lighting many captive reefs but, as said, they cost a lot to run particularly when several bulbs are in use on a large reef. Another downside is the heat they emit, which can have an effect on the seawater warming it up. This could be helpful in reducing the requirement for heaters but of course the lights aren’t on all the time. In some circumstances this seawater heating effect demands the use of another electricity eating piece of equipment, the seawater ‘chiller’.

The future of lighting is here already but still developing. LED systems are being sold and have been tested by respected experts who have declared them to be fully acceptable for marine life. They have a more reasonable appetite for electricity. They are tailored for spectrum and do not heat up the seawater (some use fans to divert heat away). Advanced arrays can even be programmed to simulate clouds passing and the gradual change from day to dusk to dark and vice versa. The downside at the moment is cost.

So what else? Skimmer efficiency might well improve but that isn’t ‘future’ but normal day to day progress, and the scope for such progress must be fairly limited. Mother Nature isn’t going to be ‘futured’, nature is what it is (though evolving nature is not denied of course).

The marine system now has a main display aquarium with live rock (which may well be manufactured by the aquarist or stockist and not come from the wild reef). In many cases there’s a sump. Sumps nowadays perform one function such as for example a deep sand bed, or could have an additional section containing a material filter etc.

The future of the marine aquarium could be lighting that is, on a reef anyway, LED’s. The display aquarium will be of various sizes as now. There could be a fitted unit to go beneath the aquarium which will contain the filter and other seawater treatment equipment required depending on the type of aquarium, fish only or reef. This is happening now of course, but mostly in a restricted way. The unit fitted could be, subject to depth available, tiered, that is, seawater could leave the display aquarium and flow through a top row of say two or three units, fall to a lower row before being pumped back up to the display aquarium. The seawater could pass through for example a skimmer, heater, deep sand bed, algae bed, carbon/phosphate remover, and pump unit plus circulation if driven from below, not necessarily in that order.

Not much difference there really from now, the difference being that the system is entire and contained, more so than it is now. It would remove all equipment from the display, even pumps if piping were routed from below. The restriction would be, as it is now, on space availability below the display – it’s still necessary to service the various areas, plus lighting could be required.

We have wonderful successes with marine aquariums now. The systems have advanced so far from the former dead white coral decorated aquariums of not that long ago. The main advance has been that aquariums are now more natural. Allowing the aquarium to have more ‘natural’ areas available with the seawater passing through must be good? There also isn’t a reason why creatures that we don’t really want in the display aquarium couldn’t be kept provided that the environment is suitable, that is it isn’t cruel.

Looking at the above it’s clear that much of the ‘advance’ is being done by some advanced aquarists anyway, who use multiple units to house various items to ‘naturalize’ the system more. Also it could be that little will change with most aquarists as space limitations apply and the ability of science to advance the aquarium is restricted, given the requirements of nature. Any advance in the future will probably be much less than from the sterility of the past to the ‘natural’ aquarium of today.

It’s interesting though.

Seawater Flow, It Matters

Corals have definite preferences for seawater flow. Some, such as many hard corals, prefer high flow and others, including many soft corals, prefer a lower flow. The general guideline for seawater flow with a soft coral display is 10 times the net seawater gallonage per hour, and for SPS corals 20 times or more.

There are different types of flow and basically the one type that should not be striking corals is laminar, or flow moving in a straight line. The type of flow required is turbulent, another way of describing it is chaotic. This flow brings food to the corals and helps remove waste.

I run a soft coral aquarium, it has been running for just over eight years now. I prefer soft corals as though they aren’t quite so ‘reefy’ they move in the flow and have some lovely pastel colours. In the top area of the aquarium the current is quite strong but lower down it is considerably less.

The display includes ‘mushroom’ corals, I believe them to be Ricordea species (though I’m ready to be corrected!). They prefer a lower seawater flow so that they can expand fully. The photo above shows these, though they are the ones that have colonised an area that is in higher flow seawater. They measure around 3 inches diameter (circa 7.5cm) and are clearly being effected by the flow – their edges ripple and lift. Therefore the mushrooms have minimized the effect the flow has on them by keeping their size down.

The photo above shows one of the original mushrooms that has been placed in a low flow area. This time there isn’t a problem with seawater flow, the coral has expanded to a considerbly larger diameter, about 7 inches (circa 18cm). Though the coral edges and surface do move a little it is not particularly significant. The coral is also free to take up different postures, sometimes with an undulated surface and sometimes with an upturned edge. This wouldn’t be possible with stronger flow.

So to get the best display from a coral it needs to be in the area it prefers and has adapted to in its natural habitat. All that is needed is a little research on seawater flow and lighting needs.

Remember The Lighting

What is the most important part of a marine system? Lighting? Well no, it isn’t, seawater quality is the number one with both fish only and reef aquariums.

High seawater quality means there shouldn’t be any indication of ammonia or nitrite. Nitrate should be as low as possible (the guideline for a reef system is less than 10 ppm (parts per million) and for a fish only less than 30 ppm. Phosphate should preferably be undetectable. pH should be stable in the region 8.1 to 8.4. SG (specific gravity) for a fish only should be stable within the range 1.022 to 1.025, and in a reef system 1.024 to 1.025 (there are variations with SG which more advanced aquarists use for specific purposes). With a reef system there are more seawater parameters that could be monitored but those given are the basic ones.

So what has seawater quality got to do with lighting, this text is about lighting according to the title.

There are occasions when an aquarist is completely at a loss to explain why the corals are not as they were, with reduced growth and less expansion. Tests have been carried out on the seawater and it is top notch. What could be the problem? Perhaps a disease that is hard to spot? In fact it could be the lighting. Great care is taken when setting up a reef system to ensure the lighting is suitable and the corals, hard or soft, will confirm this.

With a fish only aquarium the lighting is not of such great importance. Its function is to permit the fish to see and the aquarist to see the fish. In addition, if the lighting, which is usually fluorescent tubes, is chosen with care the fish colours can be enhanced. Some colours react really well to ‘marine white’ tubes, and likewise to blue (actinic) ones. There isn’t any reason why more than two tubes cannot be used, but at least two should be in use, say one ‘marine white’ and one blue (actinic). Doing this not only assists with fish colouration, it permits the aquarist to create a ‘dawn/dusk’ sequence. Using electric timers, the blue tube comes on first, then half an hour later the white. At the end of the day the white goes off followed by the blue. This avoids washing the aquarium with sudden light and plunging it into instant darkness, both bad practices.

The reef aquarium is a different story. With these systems lighting is a close second to seawater quality. Most of the corals commonly kept have zooxanthellae in their flesh. Zooxanthellae are single celled algae and the coral gets its colour from them. In addition the corals obtain food as ‘rent’ from the algae; authorities have quoted the level of food supply as 80% or more. Algae, as other plants, require light in order to photosynthesize. The light needs to have sufficient power to penetrate the seawater to the depth of the corals and reach the algae. Power is measured in watts (W). If power is insufficient then the algae will get too little, this is why different power requirements are quoted for aquariums with different depths. In addition, the spectrum needs to be suitable. Light is measured in Kelvin, otherwise known as the colour temperature. Though there is more than one colour suitable for photosynthesis with some corals, blue is the one commonly used by aquarists. Blue penetrates deeply into the seas and oceans. Generally all light types use the Kelvin scale. If metal halide lighting is in use, the bulb(s) commonly used are 10000K and 14000K. The higher the number, the more cold or blue the light appears. Many aquarists use blue (actinic) fluorescent tubes alongside their metal halides. Many commercially produced metal halide arrays incorporate these tubes.

With reef lighting it is also advantageous to have a ‘dawn/dusk’ sequence. Whether the main white lights are fluorescent or metal halide, having blue tubes allows the sequence to be arranged.

So corals, or rather the zooxanthellae in their flesh, need lights that have a suitable colour and in addition the lights need to have enough power to penetrate the seawater.

Provided the aquarist has chosen the correct lighting system in the first place and other requirements are as they should be, the reef display should be lovely. This continues for longer than a year or more when eventually the aquarist notes that the corals aren’t as they were, as said earlier. There appears to be a slow reduction in extension. Perhaps there is a slight and maybe continuing change in colour. Again as said, the aquarist gets out his/her array of test kits but nothing appears wrong, the seawater is still of high quality. How about the lights?

With a fish only system there doesn’t need to be too much concern about the lights. As said they are normally fluorescent tubes and need changing when there is clear discolouration or blackening at the end of the tubes. It is not long after this point has been reached that the tubes are likely to start flickering or fail.

With a reef system the lighting needs more careful monitoring. To the aquarist’s eye there seems to have been no change to the light, as the tubes and/or bulbs switch on normally and they seem just as bright. This is not so however. As time passes the tubes and/or bulbs start to reduce in power which means that, given time, less light will reach the zooxanthellae. In addition, over time the spectrum shifts slowly and the painstakingly chosen lights emit a changed colour, again something the corals will not appreciate.

The best way that a reef aquarist can proceed is to keep a notebook; it only needs to be a small one. In it can go all sorts of memory joggers – including when the lights were first turned on. The manufacturers usually suggest in their documentation how long the lights should maintain their original specifications. There is considerable discussion within the hobby about light reduction/change periods, some suggesting that lights should be changed every three months. I have no facts or scientific reports to argue with, but I feel that period is definitely safe but rather short. Changing the lights no later than one year seems to be a reasonable general guideline. My reef is lit by a fluorescent array, and I change every nine months and have not had any problems.

The aquarist carries out many maintenance activities, a number of which are quite rightly concerned with seawater. There are the test kits that need to come out of the cupboard regularly, the routine seawater changes that partially replace lost trace elements and dilute the sometimes troublesome nitrate. Then there’s cleaning that very useful device the protein skimmer and ensuring that seawater flow is optimal. Plus the rest.

The lights are just there. They may get an occasional wipe with a damp rag but that’s usually all. They’re very dependable and all that is needed is a bulb/tube change after a specific time lapse. This will keep the corals happy if other parameters are good.

Happy corals mean a happy aquarist.

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Natural Seawater – Is It Recommended?

Mother Nature provides the habitat for the livestock that we aquarists keep in our fish only aquariums or reef aquariums, and this, of course, is the wild reef. Mother Nature is also the provider of the other obvious essential, and that is seawater.

Having written the above it would seem absolutely wrong to state that natural seawater is not recommended. So it would be – natural seawater is recommended.

However, is it recommended overall, for the majority of aquarists? This needs a bit more care, and two questions arise. These are first, the ability to collect the seawater, and, second, before any attempt is made to collect it, what is the seawater’s condition?

Not all aquarists live within easy travelling distance from the sea, but there are a fair number where it could be a viable proposition. So in this case the first consideration is practicality.

Seawater is heavy, it ways somewhere towards 10lbs per gallon. So to do, say, a 10% water change a good few gallons are required. Not so many for a nano aquarium, but increasingly more as the aquarium gets larger. Also of course, some aquarists do water changes that are more than 10%.

This water has to be moved from the sea to the aquarist’s home. This means there needs to be sufficient containers of seawater safe construction which are also strong enough for the journey. In addition there must be transport that is robust enough, and roomy enough, to carry the full containers.

If the aquarist cannot meet these requirements then the obvious answer is to use one of the available commercial dry salt mixes. Transportation problems for these mixes are zero as they come in different size packs, can be transported by car, or can even be delivered to the aquarist’s home.

If the aquarist can meet the transportation need, then another consideration arises. This concerns the question of pollution. It is very unfortunate that many coastal areas are polluted with industrial waste and/or agricultural run-off and the like. The aquarist must be absolutely sure that the seawater being collected is clean. There might be a facility nearby who could advise on this matter. If not, it is better to play safe and use a dry salt mix.

If the coastal water is polluted, then natural seawater could still be used. By going considerably offshore, it is possible or maybe probable that the seawater will be unpolluted – but not definitely so. Again, the aquarist must be certain of the condition.

Going offshore brings the transportation problem back. Is there a boat available? If the aquarist is also a yachtsman all is well and good. If not, the only means is to hire assistance, and then cost is creeping in. In the latter case, the effort may not be financially worthwhile, so again a dry salt mix could be the preferred option.

Using natural seawater brings up another possibility, and that is disease or the introduction of unwanted life. This applies particularly if the natural seawater being obtained is warm.

This danger can be minimised. The collected seawater can be kept in the containers in the dark for a week or better two, and at the same time have it passing through UV (ultraviolet) lamps. These can be obtained specifically for aquarium use. If there were more than one container, they would have to be connected or the aquarist would need more than one UV lamp. After the mentioned period, the seawater could be used after where necessary being heated to the required temperature, and after any sediment that had accumulated on the bottom of the container(s) had been siphoned out.

There is one more consideration. This is that the seawater could still need supplementation. Just because the seawater is natural does not mean that in a reef aquarium there will not be a need for calcium addition and the like. In the confines of the aquarium, a heavy demand will have the same effect as it would if synthetic seawater were in use.

Some aquarists have reported that using natural seawater has a wonderful impact on their captive reefs. This is of course anecdotal but there isn’t any reason not to accept the reports. Perhaps there is some ‘magic’ in natural seawater that makes a difference?

Looking at so many captive reefs that use commercial salt and can be viewed on the internet and in reality, and considering the great success and beauty of these reefs, there isn’t any real need to doubt modern commercial dry salt mixes.

If the aquarist can meet the demands for using natural seawater, then all is well. Most aquarists will be happy using commercial salts.

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