Shaping To Circumstance?

The beauty and diversity of a wild reef is well known. Fish and corals have adjusted to their niche.

What about the captive reef? The aquarist does his/her best to meet the needs of the corals (and fish) to try and ensure their health and longevity. The fish and corals have preferences. For a fish example, many wrasse like to bury themselves in sand and so the aquarist provides it in sufficient depth. Corals have a spot on the reef too, where they are subject to varying seawater currents, light intensity and spectrum. The aquarist tries to meet these differing needs as well.

What if the coral receives continuous directional seawater flow, not strong enough to cause damage, will the coral react? Well, yes, it usually will over time. A land based tree subject to nearly continuous directional wind will lean away from the wind, thus reducing the trees resistance to it. So it is with corals - a coral with directional water flow will tend to grow heavily influenced by that flow. If it is a branching coral, probably particularly a ‘hard’ type, it will reduce the resistance to the flow by growing ‘with’ the flow - in other words it will lean away from the flow.

On the wild reef a hard coral near the crest where it is subject to great turbulence and wave power will have short stubby branches to present less resistance to the water. In areas of less flow, the branches will be longer and possibly more slender.

In a similar way some corals react and grow according to light availability. The shapes are natural, and these are the normal shapes the coral is expected to be. The coral in the wave area with short branches receives considerable light as it is near the surface, so the short branches are not a problem. The coral lower down with less seawater turbulence has longer branches and thus more is exposed to the lowered light level. Some corals form horizontal plates which often overlap one another, and these present a large area for light to strike.

I keep a soft coral reef and wonder if the same thing applies to these. I know the shape and the lean of the coral can be influenced by water flow, but wonder if these corals can alter their growth to gather the light they need? What if they need more light and are in a position too low down to get it?

I have been watching the growth of a soft coral for quite a time. It appeared very close to the bottom of the reef, and the growth is slow. The water flow is quite gentle in the coral’s area but is sufficient and multi-directional, and I don’t believe this influences it particularly.

The coral is a normal branching type, that is, it would normally grow vertically with several more or less vertical branches, with a few side growths as well. It started very small, and I assume it is a ‘dropped’ branch or similar as I didn’t place it there.

The aquarium is 24″ in depth and lit by an array of fluorescent tubes (marine white and actinic blue). I assume the coral’s growth is slow as it receives low light.

The interesting thing is, the coral spent a long period not growing toward the light as might have been expected, but growing horizontally. I wonder if this was to gather as much light as possible by presenting the largest surface to the available light as possible? The coral is now showing vertical growth in several places, so maybe it has enough energy now to be able to do so?

I don’t know what the answer really is, but the above seems feasible as fluorescents are not able to punch much light into nearly 24″ of seawater.

There’s a photo to show the coral (it is now about 5″ across) - I’m not a photographer so I apologise for any shortfall.

Aren’t marine aquariums interesting! There’s always something to watch, just for pleasure or to ponder over.

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Tags: Aquarium Lighting, aquarium-coral, Coral Reef, hard coral, reef-tank, soft coral

Coral Problems

Anyone sitting down with a good gardening book can be taken aback by the number of problems that could be met by any particular plant. Some are hardier and more resistant to disease than others. This is of course true for all life forms.

The marine hobby world, be it a fish only aquarium or reef aquarium, is no exception. The fish can fall to disease, and so can corals.

This is not intended to be a cover-all for aquarium coral problems. The subject would be far too large. However, an attempt will be made to consider perhaps the more likely troubles.

To avoid as far as possible any problems arising in the first place, there are four areas that need attention.
[Read more]

Tags: aquarium-coral, coral, home-aquarium, marine-aquarium, saltwater-aquarium

Good Starter Corals For The Beginner

When starting a new [tag-tec]reef tank[/tag-tec], especially if you are a beginner to the hobby as I am sure you may by now appreciate there is at times quite a lot to learn.

Starting a [tag-tec]reef aquarium[/tag-tec] is only as hard as you allow it to be. Why learn all about advanced water chemistry for example at the very beginning - learn the basics first, get your aquarium running and then carry on reading, studying and learning.

Why make starting an aquarium harder by including corals in your aquarium where you have to learn a lot about how to care for and maintain them. There are some corals which are exceptionally hard to care for so why not keep some of the easier to keep corals whilst you are learning the basics and as you learn more and your aquarium ages then you can add more. [Read more]

Tags: aquarium-coral, coral, saltwater-aquarium-setup, saltwater-coral, starting-a-saltwater-aquarium

Soft Coral Fast Recovery

My [tag-tec]soft coral[/tag-tec] reef (I love the way soft corals sway in the current and the subdued pastel colours mix together) is growing very well. As Peter has taken on a rather sad aquarium that he has in the process of recovery (see ‘An Aquarium System in Trouble - A Slow Recovery‘), I decided to cut some corals and pass the cuttings on.

Now [tag-tec]coral propagation[/tag-tec] is a worrying thing for most aquarists including me. There they are on the reef healthy and expanded. Then along comes John with a very sharp pair of scissors! First of all what to cut? Decided. Where to cut - what impact on the reef appearance? OK. What about the health of the coral, is the cutting method correct? OK. Hesitation, do I really want to do this? Yes, go ahead. Corals cut, cuttings shrink to a hard small lump that looks as though it will never live again. The coral from where the cutting was taken closes and looks thoroughly miserable. [Read more]

Tags: aquarium-coral, coral, coral-frag, propagation-reef, toadstool-coral

Aquarium Additives and Soft Corals

Keeping a seawater aquarium nowadays is a generally straightforward affair. Provided the design and setting up is satisfactory and the aquarist does the necessary periodic maintenance properly, the aquarium will give pleasure for a long period.

Commercial seawater mixes are good overall. The mix will provide adequate levels of elements in the seawater, but checks should still be made, particularly when the aquarium is matured and settling and onwards, to ensure that important parameters are as they should be.

The levels required depend of course on what is being kept. The fish only aquarist need hardly bother with any additives, just ensure that water quality tests are done (nitrates, pH etc) as these measurements are important, and action needs to be taken if anything is amiss. If [tag-tec]aquarium water changes[/tag-tec] are done it is likely that the seawater will remain fine, but maybe after a time from the initial mix end up, for example, with a fairly low calcium count. Alkalinity could also be low. None of this particularly matters if the fish are healthy and general tests are acceptable.

The aquarist who keeps a reef needs to pay more attention. No matter if there are fish present, the corals and other life create a need for closer attention. A soft or hard or mixed coral reef needs calcium, for example.

Soft corals do not demand high levels of calcium but it is worthwhile to maintain a fair level as there is a demand. I have always kept a notebook with each aquarium I have owned. I have a ‘thing’ for [tag-tec]soft corals[/tag-tec] so they are the type I have always stocked. Looking back at my records, calcium has generally been between 350 and 400 ppm. I did an experiment years ago with soft corals and calcium. Though I kept dates etc it cannot be deemed scientific, but should be considered as anecdotal.

I increased calcium by addition to 450 ppm for a period of 3 months, a period lengthy enough to have an effect. Routine water changes were regular at 10% weekly. The calcium level did vary a little but not much. I could detect no change in the health or growth rate of any coral. The calcium level was allowed to fall again and the notebook indicates no mishaps or worries arose. I know of a soft coral reef where the calcium level is a little over 300 ppm, The soft corals show no problems. If the aquarist wishes to raise calcium levels, it should be done slowly. There are commercial preparations that can be purchased and the aquarist should adhere to the manufacturer’s instructions in line with the net gallons in the aquarium. If the aquarist is serious about maintaining calcium levels and has a large aquarium, the use of a commercial [tag-tec]aquarium additive[/tag-tec] may be too costly and impractical. In this case consideration could be given to the use of a calcium reactor. If calcium levels are raised then attention needs to be given to alkalinity.

Please follow this link, an explanation is given about the relationship:

http://www.advancedaquarist.com/issues/nov2002/chem.htm

Also see ‘Alkalinity - What Is It and How Is It Controlled?‘ under Water Testing on this site (ie. Aquaristsonline).

With soft corals, some experts suggest the addition of iodine. Iodine in natural seawater is at very low levels, 0.06 ppm. As said, very low. Overdosing must be avoided when using commercial preparations. Again, strictly adhere to the manufacturer’s instructions. One problem with iodine supplementation is that, at least to my knowledge, there isn’t a reliable test kit available. If this is still accurate, the aquarist who is supplementing iodine according to instructions, and also doing, quite correctly, routine water changes, will not know if the iodine levels are rising, stable, or dropping. I would suggest not supplementing, and see if the corals remain healthy and growing. If they are, don’t supplement iodine.

There are commercial preparations available that claim to supplement important multiple trace elements. There is no dispute with that claim. However, if you feel you must supplement with one of these preparations, for example because activated carbon is being used, be aware of what is going into the seawater and also the reason why. If the manufacturer is worth his salt (no pun intended) the instructions will generally advise what and why.

Remember, with any supplementation be aware as far as possible of the levels in the seawater. This is not always possible with ‘trace element’ concoctions. Do not overdose, a little extra does not do a bit more good. Some aquarists advise that ‘if you can’t measure it, don’t use it.’

It is best to watch the soft coral reef, observing how the corals expand and grow. If all is well, routine water changes may be the only action required.

Finally, on any reef, soft coral ones included, there is normally more life than just the corals - snails, tiny shrimps, decorative algae and the like. Having increased and controlled levels of for example alkalinity can enhance the production of this additional life, all adding to the wonder and complexity of the aquarium reef.

Tags: aquarium, aquarium-coral, calcium, Coral Reef, saltwater-aquarium

How To Acclimitise New Corals And Fish Correctly

It always amazes me how many people I see or talk to who purchase a marine animal, take it home, open the bag and pour it into their aquarium. I can never understand why some people do not acclimitise their purchases properly, it could be laziness, lack of knowledge, impatience etc but one thing is for certain life is on the line here so it must be done correctly.

The purpose of acclimatisation is simple - the water that the animal is packaged in may have a different temperature, pH and salinity than that of your aquarium. Aquatic life (especially corals and invertebrates) are very sensitive to minor changes in water parameters therefore acclimatisation is a definate requirement for success. [Read more]

Tags: acclimitise, aquarium, aquarium-coral, aquarium-fish, AQUARIUMS, marine-fish

Coral Propagation

Any aquarist worth there ’salt’ has a desire to see the reefs in nature continue to thrive. Fortunately a lot of the illegal harvesting has ceased and the natural reefs are starting to become more understood and admired.

Unfortunately however, mankind is making it hard for these reefs to survive and many are in decline. This makes me very sad and I am sure a lot of others as well. As saltwater aquarists we all have a passion and love for these beautiful animals - even if we stop keeping an aquarium for a while that passion does not dwindle. [Read more]

Tags: aquarium-coral, book-coral-propagation, book-of-coral-propagation, coral-glue-propagation, propagation-reef

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