The Dusky Dwarf
June 30, 2009
There are so many fish that could tempt an aquarist but many of them have an attribute or two that means they cannot be chosen.
One of the most beautiful fish types are the angels, for example the emperor angel (Pomacanthus imperator) and the queen angel (Holacanthus ciliaris). These are certainly beautiful but cannot be kept by many aquarists because they grow too large.
So the aquarist with a smaller aquarium has to ignore angelfish? Well, no fortunately not. There are some angelfish that are suited to smaller systems and are also beautiful. These angels are generally termed ‘dwarf’ and there are some really stunning ones. Surely the flame angelfish (Centropyge loriculus) is well known. There are a good few others.
The angel referred to in the title is commonly called the dusky angelfish or coral beauty, the proper name is Centropyge bispinosus.
As with other dwarf angels there isn’t a problem with eventual size as fully grown the fish could be around 4 inches (circa 10cm). On purchase the fish are likely to be in the region of 2 inches (circa 5cm). The fish should not be kept with others of its own kind as usually aggression will occur. It has been known for two dwarf angels to be kept in a smallish aquarium together without mishap but this is unusual and best avoided. If an attempt is to be made to keep two Centropyge types the two fish should differ in size and colouration. In particular, the aquarium should be large with plenty of rockwork which affords the fish many retreats and possibilities of territory. The dusky angel will usually settle down with other suitable fish without problem, though larger more aggressive fish could cause difficulty. Overall the fish is mainly peaceful but aggression could appear from time to time, though nothing usually comes of it.
http://animal-world.com/encyclo/marine/angels/CoralBeauty.php
As can be seen from the link picture the fish is lovely, though photographs don’t really do it justice. The colouration is not so much ‘in the face’ as, say, a flame angel’s, though lovely nevertheless. The colouration can vary a little, some fish are subdued and dusky, others brighter and more striking.
Keeping the fish is reasonably straightforward without any particular requirements except one. This is that though the fish is a general omnivore it should have access to algae. The fish likes to take algae from the aquarium viewing glass and rock surfaces but cannot be considered as a good algae controller. The overall diet should be varied even with algae present, consisting of marine flake, de-frozen brine and mysis shrimp and similar. Food enriched with spirulina algae is a good idea. As always seawater quality should be high. There should be rockwork installed that permits the fish to find a cave or similar for security. The fish is suitable for a reef system though like many fish it could nip at fan worms and possibly even some corals. Usually it is well behaved but there could be exceptions!
The fish when kept in a good environment is considered to be reasonably hardy. However, some aquarists consider it not to be an ideal beginner’s fish as some experience is needed first. This is because of the early mistakes, usually to do with seawater quality that a beginner could make.
Adding one of these fish to a suitable display will not disappoint the aquarist. As stated elsewhere by an unknown source, the dwarf angels are God’s gift to aquarists. It is easy to see why.
Why Should Alkalinity Be Higher In The Aquarium?
June 28, 2009
The marine aquarium can be so beautiful if the aquarist does straightforward routine maintenance as required, and doing this maintenance includes attention to the all important seawater quality.
Seawater quality is maintained by routine changes of sufficient quantity, and at the same time tests are completed to ensure that the required standards are met. These tests include specific gravity (SG), pH, nitrate and for a reef could include calcium and similar. Some aquarists continue to test for ammonia and nitrite after the initial maturing process. Alkalinity is a test that is useful to marine systems too.
It would seem fair to think that Mother Nature would know best in these matters and the alkalinity level in the wild is 7 to 9 KH*. So perhaps we should keep out aquarium seawater at the same level.
We could maintain a natural level and hopefully all things being equal there wouldn’t be any problems. However, we are not talking of the vastness of the seas and oceans where seawater quantity is measured in cubic miles; we are talking about aquariums where even a large home system of 500 gallons is, by comparison, very tiny.
Most aquariums are fully stocked whatever system they are. The life in the aquarium puts pressure on the seawater in several ways and one of them is the acid/alkalinity balance. We know this measure as it uses the pH scale, and we want a pH of between 8.0 and 8.4 which is on the alkaline side. The life functions in the aquarium constantly try to reduce this pH towards the acid side, something we do not want.
Prevention of the reduction in pH is achieved by the ‘buffering’ capacity of the seawater, in other words its ability to resist changes caused by acidic substances. The ‘buffer’ is mainly the carbonate/bicarbonate content of the seawater. In certain circumstances the buffer could be seriously weakened or even exhaust and the pH would fall which is detrimental to the livestock.
Dry seawater salt as purchased by most aquarists for seawater make-up has a buffering capacity usually around natural levels. However, many aquarists boost the buffering capacity of their seawater by adding carbonate/bicarbonate powders. These powders are usually mixed in some seawater before being added to the aquarium, being careful not to hit corals etc. The powders are sold commercially and are very easy to use.
In an aquarium it is considered best to maintain alkalinity from 8 to 14 KH.* It is not recommended to raise the level above 14 KH.* The recommended level of 8 to 14 KH does not mean the level can vary within these limits, it should be reasonably stable at the chosen point, ‘reasonably’ meaning that some variation over say a week will not usually be harmful. My system runs at 10 KH and needs boosting to an extent weekly.
If the aquarist measures the alkalinity of a fully stocked system on a weekly basis and keeps a note, then the trend of the aquarium can be seen. The amount of buffer that needs to be added is easily prepared week to week. Testing can be reduced once this requirement has been discovered but should not be abandoned.
If pH is a problem and it is falling despite routine seawater changes and good husbandry in feeding etc, then perhaps the buffer capacity needs attention. Increasing the buffer by 1 KH week to week will not do harm. I have found a good alkalinity level is also beneficial to the growth of welcome encrusting algae which can beautify the aquarium.
By the way, if the desire is to measure alkalinity by mg/l, then multiply KH by 17.9.
(*Reference: Marine Atlas. Helmut Debelius & Hans A. Baensch)
The Royal Gramma
June 25, 2009
Mother Nature provides some really lovely life forms; they come in all sorts of shapes and colours. Fish are usually the number one life form for the marine aquarist (for others is it perhaps corals?).
One fish that is an excellent addition to many aquariums, fish only or reef, is the Royal Gramma which is the common name, the proper name is Gramma loreto. In my opinion they are often better on a reef as the usually lower fish population means these systems are less ‘busy’. However, note that the fish could be ‘nippy’ with some other type tank mates such as snails and possibly feather dusters. When I had one of these it definitely added colour, and when the scene was lit by actinics alone this was considerably enhanced.
This is one of those fish that nature has painted differently at the front and back. From roughly mid-section it is yellow including the tail, and forward of this is purple/blue. There is a dark diagonal line through the eye and also a dark spot on the dorsal fin. The fish is capable of growing to about 4 inches (circa 10cm) including the tail, though it is usually smaller on purchase.
Once settled the fish is not bothered by bright light and should be seen quite regularly. It is also happy under lower light levels. However, for the fish to feel secure it is necessary for caves and crevices to be built into the rockwork, which is applicable to many fish.
A potential problem is that the fish has been known to jump; perhaps this is an escape ploy. It would seem reasonable to assume that if there are crevices and caves available for security, then jumping is less likely.
The fish defends itself by a display of aggression when it faces the opposition with its mouth wide open. The fish is not particularly aggressive normally (unlike for example many damsels) and is best kept with other small relatively non-aggressive fish, but avoid dotty-backs as trouble could occur.
Usually it is best to keep one fish, though in a larger reef aquarium with plenty of territory and hideaways it could be possible to keep two.
Where a high quality environment is maintained the fish is easy to keep (in marine terms) and resistant to disease, so a reasonably long life could be expected. When the fish is first introduced to the aquarium it could well be choosy about food and not eat a lot, which is always a worry with a new fish. However, this period should soon pass and the fish should eat almost anything, including marine flake and de-frozen foods.
Aquarists are always observant and could become worried if the Royal Gramma is seen upside down in a cave. This isn’t usually a problem indicator; perhaps it is linked to spawning behavior (I’m not aware of any proven reason).
In a suitable environment the Royal Gramma is a great fish to keep with its colours and peaceable disposition – in addition, the fish is hardy and easy to feed. So overall the fish represents a winning combination.
The link is to further information about the fish and also photographs:
http://www.fishlore.com/Profiles_Fairy_Basslet.htm
A Worrying Failure
June 23, 2009
Marine aquarists make use of varying types of equipment on their fish only or reef aquariums. This equipment is generally reliable nowadays but nevertheless any device has the potential to fail.
There are many canister filters in use for either mechanical or bio-filtration. Though live rock is the bio-filtration of choice for the modern aquarium, canisters are still in use by many for this essential task. There isn’t any reason why they shouldn’t be, though there are drawbacks.
Live rock is able, within reason, to deal with nitrate. In other words live rock should perform the full nitrogen cycle. This is the major drawback with canister filters, nitrate is the end product. This is because the bio-media within the canister is oxygen rich and there isn’t any need for oxygen to be obtained elsewhere. Nitrate reducing bacteria require an environment very low in oxygen which forces them to seek an oxygen supply elsewhere; nitrate is present so oxygen is taken from that which breaks the nitrate down. It follows that an aquarist using a canister filter needs to keep a closer eye on nitrate levels and carry out the requisite correctly sized seawater changes.
Another advantage of live rock is that there isn’t anything to break down, as opposed to a canister filter where there is an electric pump. As already said modern canisters are reliable though recommended models should be sought when purchasing, but what if a breakdown does occur?
Failure of the electric motor means that the whole function of the canister ceases as seawater flow stops completely. When an aquarist does routine maintenance the output from various devices is checked, an operation that takes hardly any time. However, it is more likely than not that a failure will occur at an inconvenient moment. Canister electrics are usually very quiet nowadays and there isn’t any indication of trouble apart from seawater output ceasing. So the first thing is to note the output anytime possible, such as at feeding time and when starting to simply observe and admire the aquarium. It only takes seconds.
A stopped canister filter should be switched off and then on again a couple of times, this sometimes frees up the motor. Don’t count on it though! If the motor does re-start then as soon as possible check the shaft and impellor for debris. However, before attempting to re-start by switching off and on note the comments in the following paragraphs.
Once the output from the canister is noted to have stopped there isn’t any way of knowing when it stopped. This is a worry because involved is the life support for the system, the bacteria. How are they faring?
It could be that the fish have been acting strangely and that is how the lack of seawater output was noticed. If this is the case then the failure occurred quite some time ago as there has been time for toxics to build up in the seawater. The first action is a seawater change, the size of which depends on the severity of the situation. If the fish are really obviously in trouble then 25% is not excessive, more if necessary, and the change should be done as soon as possible. The aquarist should be prepared to carry out a further change if necessary.
The aquarist should ensure that other equipment, namely the protein skimmer and seawater circulators, are working at maximum efficiency to ensure maximum oxygen intake and minimum bio loading (the skimmer should remove substances reducing the load on the bio-filter).
A regime of seawater testing should be introduced. Once the situation is under control the tests can be done once daily, but it is often better and more reassuring for the aquarist to do tests morning and evening. The tests are of course ammonia and nitrite. The only ongoing acceptable test result is ‘nil’ or perhaps more accurately ‘undetectable’.
If it is found that the canister filter electric motor has failed but the fish are not showing symptoms of distress then the failure is probably quite recent. Again, test the seawater and do a change if necessary.
In both cases, fish distressed or not, cease feeding until an effective bio-filter is back in operation.
The speed that toxics develop in the seawater depends to a large extent on the fish numbers present. Corals present a far lower bio-load.
As soon as possible deal with the canister filter. At this point it is known that switching it on and off didn’t work! Ensure it is switched off and disconnect from the tubing. Check the impellor and shaft, there could have been a failure, if jammed the problem can usually be sorted out. If there is a breakage spares are usually available, obtain them by the fastest possible means even if it incurs extra cost. (Obtain the spares from the local fish shop if possible to avoid any delay.) Check that the input and output tubing is not blocked, this could occur over time.
If the electric motor itself has failed then a new canister filter should be obtained (or better two, see below). When the replacement device is available bio-media can be transferred and if required extra added. Until the new device arrives the bio-media already held should be kept within the aquarium seawater preferably in a high flow area so that at least some of the bacteria are retained. When the new canister is running there is a clear need for monitoring the seawater condition, as it will be similar to though not as extensive as maturing again. Seawater quality can be maintained by additional seawater changes, new seawater should be available at all times until the aquarist is sure all is well.
If the canister has been off for a long time do not re-start it and allow it to continue running. Disconnect and drain the internal seawater out completely. Refill and then start and run. This is because there is a danger that the seawater within the canister could be heavily contaminated. If the canister is likely to have been off for only a short period, just re-start. It is worthwhile carrying out daily seawater tests for a week in either case to ensure the bio-filter is effective. After re-start, feeding should be with considerable caution as the bio-filtration may well be weakened and need to re-build. Again, ensure that the protein skimmer and seawater circulation pumps are at maximum efficiency.
To largely avoid a problem such as described, unlikely as it usually is, when the system is designed it is a good idea to employ two canister filters. This will of course mean a little more cost, but the filters can be smaller. Instead of obtaining one which can handle the net gallonage of the system, obtain two. These together in total should handle the net gallonage, but it is a good idea to have both of them a little oversized. They can be routinely serviced alternatively so there isn’t any extra work generated. If the need for canister bio-filtration is removed in the future they are useful for mechanical or other types of filtration.
It is generally unlikely that a modern canister filter will fail, particularly if it is adequately routinely serviced. If it does fail the shaft/impellor could be affected by accumulated debris and/or calcareous buildup, or tube blockages could be present. Observation is the main preventative.
It’s A Sunny Life
June 20, 2009
We marine aquarists are lucky in more than one way, and a part of this luck is that our aquariums are always sunny, no matter what Mother Nature has to say about it, wherever the aquarist may live.
Day in, day out on comes the lighting system and, surprise, the sun is shining and does so all the time until dusk when the actinics are on alone. Ok, there are some who have very advanced lighting systems (Led’s) which can simulate cloud cover but for most of us it’s a permanent clear sky.
Of course there are those aquarists who live permanently in a naturally sunny climate. There they are with a coral reef to dive on but then human nature being what it is they are not always completely happy.
A few years ago – cripes, as long as that! – my wife and I were in Barbados for a holiday and were in the process of hiring a car for sightseeing purposes. The garage proprietor was a friendly chatty type and the talk came round to reefs, I was asking which would be the best area for snorkeling. It turned out that he was a marine aquarist. How very widespread this hobby is! Sadly I never got to see his aquarium but he advised he obtained his fish (and corals?) from the reef. I mentioned I was surprised as he had a huge natural ‘aquarium’ to swim in, but he said it was wonderful to see the fish within his home.
When talking it turned out that what he really, really would like was a holiday such as we were having, two weeks or so away. ‘What – and you live in such a lovely sunny place’ was my response. He said he would love to take his family to England. England, very beautiful but well known for its cloudy days and rain.
It just goes to show that perspective depends on many things, one of them at least being what you haven’t got. So my ‘aquarists are lucky’ is probably down to the fact that there aren’t any coral reefs near me and the sun doesn’t always shine.
My soft coral reef continues to do really well. I do the required routine maintenance and spend time admiring the aquarium picture. I still have wars with those xxxxxx aiptasia anemones and have to admit that this is one area where I have not been successful, having failed to eliminate them. However, eliminating these aquatic weeds in a reef aquarium is just about impossible as there are so many nooks and crannies. I attack them periodically when they are small, the reason for doing it when they are small is that I understand (from reports on the internet) that aiptasia anemones are able to release ‘emergency spores’ when they are facing oblivion, as apparently they recognize they are under lethal attack. I don’t know if these reports are correct and scientifically supported. Anyway, if correct I assume small means a lower spore count. Periodic attacks also keep them well under control and prevents them spreading.
Now summer is well and truly with us I’ve tested my 12 inch electric fan, if temperatures raise unduly it will be used for cooling.
Talking about cooling, I’m sure there are a couple of beers in the ‘fridge….
Public Aquariums
June 18, 2009
Most aquarists like to visit a public aquarium from time to time and once there are drawn to the marine areas. Usually the displays are excellent but not always, even the professionals can make mistakes or have mishaps.
My local public aquarium made a very basic mistake which was pointed out to them. In a large reef display they put a large number of damsel fish which looked very impressive at first. I say ‘at first’ because the numbers diminished quite rapidly. This was because they also introduced two rather large lionfish. Now, we all know what lionfish are likely to have for lunch don’t we. They did! Before all the small fish disappeared the lionfish were removed and now have their own smaller display aquarium.
Anyway, public aquariums are the place to see some excellent display aquariums in which creatures too large for a home system are kept. In addition there are often some reef systems on display which usually draw quite a few ‘oohs’.
The London public aquarium has various displays and the attached short video is one of them. At the beginning of the video is a water motion section, the movement presumably generated by some hefty timed pumps. Don’t worry about the colour, the video changes quickly.
The Yellow Tang
June 16, 2009
This fish is one recognized by all marine aquarists; it is very popular and commonly kept. If a splash of colour is required then this is one of the fish to consider, it attracts the eye like a magnet does metal.
The fish is properly called Zebrasoma flavescens. It is yellow all over apart from a small white area in front of the tail; this is the ‘scalpel’.
The yellow tang could grow to 7½ inches (circa 19cm). As with all fish of this type it is not for every aquarist as swimming space is required. A small aquarium is not a home for it; a suggested minimum size is 3ft (circa 91.5cm) by 1.5ft (circa 45.75cm) by 1.5ft though larger is better. If the reef structure is large this will reduce the swimming space, so even if the aquarium itself seems large enough the actual free seawater space needs to be checked.
The yellow tang is reputedly one of the hardiest of the surgeon fishes. Of course high quality seawater needs to be provided at all times. Tank mates should be compatible though even so aggression could appear, but usually with needs properly met they are peaceable enough.
Feeding these fish is not difficult, they will usually take marine flake and de-frozen foods. However, it is essential that they receive adequate amounts of algae. In the aquarium some of this could be provided by natural growth and in this way the fish is useful in keeping algae down – it should eat filamentous algae. Aquarium algae are not normally present in sufficient quantity so the aquarist needs to provide the food in other ways. One of the best methods is to purchase sheets of dried algae such as Nori. One sheet or a part of it can be held in place by an aquarium clip and left. The fish should eat it enthusiastically. It is suggested that algae is fed at least every other day, though many aquarists place the food in the aquarium everyday to ensure the fish can take it at will – any sheet algae that breaks free should be re-fixed or removed and any uneaten after a full day removed.
Brightness and colour are usually present in a marine aquarium and this fish has them plus another, movement. Properly cared for they should ‘live long and prosper’.
The video gives information on care of the yellow tang. For those who want to see a photo of the fish click on the link.
http://commons.wikimedia.org/wiki/File:Zebrasoma_flavescens_Luc_Viatour.jpg
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