There Is A Bad Reading But The System Should Be Mature

Relating to marine aquariums what is meant by ‘mature’? It means that the aquarium system is ready to support life. In fact there are two levels of maturity: the first is the initial level which is achieved after the system has been set up and the biological filter (some call it life support) has been activated. The second is when the system is truly mature, this is when the livestock is present in entirety and the biological filter has fully settled down to the task it faces, this could take many months. The first level could take many days to weeks.

The two main biological filter systems in use are live rock and canisters, the first being the most desirable. The biological filter is populated by bacteria. The bacteria deal with the toxics which, without them, would appear in seawater tests, these being ammonia and nitrite. Ammonia is produced by fish etc as a natural part of life and the bacteria convert ammonia to nitrite and then nitrite to nitrate (depending on the type of filter). In an enclosed system ammonia and nitrite are dangerous and should measure on tests as zero.

It is necessary initially to look at both types of filter separately so let’s start with the canister filter.

The canister filter is an electric pump positioned on a cylinder so that seawater can be moved from the display aquarium through the canister and back to the aquarium. It’s generally best to have the seawater intake at one end of the aquarium and the outlet at the other end, with the returning seawater exiting at the surface (this is to aid with re-oxygenation). As the seawater goes through the canister the bacteria that live on the media carry out the conversion of toxics. When the canister is first set up there aren’t any bacteria present of course. It’s necessary for the aquarist to carefully choose an adequately sized canister then obtain bacteria friendly media (some are better than others) in sufficient quantity. The bacteria have to be introduced to the media and this is best done by the use of commercially available maturation fluid which includes full instructions for use. The procedures are simple and involve regular testing for ammonia and nitrite. The filter is considered mature when readings are zero, indicating that the bacteria are doing their job.

Note that canister filters do not deal with nitrate (because of the presence of oxygen). Some types of media have claimed to be able to deal with nitrate but this ability is usually short lived. To avoid putting undesirable nitrate into the aquarium from the start before livestock are present, put intake/exit tubes into a bucket containing seawater at the required temperature. When tests indicate zero for ammonia and nitrite the filter is ready to support livestock in the display aquarium. The seawater in the bucket should be thrown away. It isn’t necessary to have the filter attached to the aquarium initially: the bacteria are being introduced to the filter media not the aquarium. In the future as the aquarium slowly matures to the second level bacteria could appear elsewhere but it’s the canister media that’s the main home for the hard working bacteria.

Live rock is probably the most used filtration. Not only does it provide the bacteria media, it ‘seascapes’ the aquarium as well. There aren’t any trailing wires or tubes to be seen. All that is required is for the aquarist to purchase sufficient ‘clean’ rock and introduce it to the aquarium making sure that there is good circulation around and, as far as possible, between the rocks. ‘Clean’ (or ‘matured’) rock is that which has been kept for a period by the retailer so that organisms that are dying or dead can be cleared away. These organisms are there because live rock comes from the sea and some of them cannot withstand the stress of transportation. If dying or dead organisms were left they could be a source of ammonia. In addition, there could be undesirable organisms that hopefully will be spotted and removed. If the aquarist is lucky some desirable organisms could survive.

Live rock is able to deal with ammonia, nitrite and in addition, within reason, nitrate (‘within reason’ means there’s a limit). This is because the bacteria require oxygen, those on the surface get it easily and convert ammonia and nitrite but those within the porous rock don’t but still require oxygen – to get it they remove oxygen from nitrate thus breaking the nitrate down.

Ok, so the aquariums set up and there’s a troublesome reading of ammonia or nitrite that shouldn’t be there.

 First of all, with the canister, is the aquarist using that all important requirement patience? The time required for a canister to initially mature varies and the need is to wait until it does. Don’t overdose the maturation fluid thinking that the process will speed up, it won’t. Follow the instructions carefully and stop dosing when indicated, often when the test turns red. What is happening is that the bacteria are building their numbers so that they are able to deal with the toxics present. If the filter media is ok and the pump operating correctly, the bad reading will go, often disappearing in a very short period, sometimes in not many hours. The sequence of readings is usually ammonia, then nitrite, then these clear. Nitrate often appears as the cycle progresses.

If the tests showed zero readings but a bad reading has returned, presumably this is during stocking. Stocking the aquarium starts when the initial maturation point has been reached. Stocking, particularly with fish, much less so with corals (corals present a lower biological load) should be done slowly. After the introduction of two small fish or even just one (in a 50 gallon aquarium) there should be at least a two week period before further fish are introduced, and then just two more, or one if it is larger. The reason is the biological filter has to adapt to the increasing load – if organisms are introduced too quickly the bacteria can’t cope and an undesirable test result is likely. Stop stocking and wait for any bad reading to go keeping an eye on fish already present. If they show signs of discomfort, carry out a partial seawater change. Testing should continue very regularly during the whole stocking period.

If a bad reading appears after full stocking is reached or is being approached and even after waiting it doesn’t disappear, check the canister filter. Is the electric pump working (is seawater coming out of the exit pipe?) They are generally reliable nowadays. Are the inlet and exit tubes properly attached? Is there a blockage preventing correct seawater flow? If no problem is found and the bad reading persists, check the capacity of the canister – manufacturers usually indicate the gallons the canister can deal with. If the canister can’t cope, mature a bigger one (mature the additional media and when ready transfer the media from the smaller canister). Perhaps there is room for more media in the smaller canister. Obtaining the correct size canister is clearly best done at the planning stage.

During maintenance, the bio-media within a canister filter can be cleaned if necessary to maintain seawater flow and general efficiency. The cleaning should be done in warm seawater (the old seawater after a routine change for example). Stir very gently. Never clean in tap water or there will be bad readings on testing!

The aquarist who uses live rock should adhere to the stocking principle outlined above. Some beginning aquarists believe that when live rock is introduced then stocking can go ahead as the rock is fully ready. This is incorrect and could be the reason why a bad reading has appeared.

Live rock is already populated by bacteria, but the adequacy of this population varies. First there are different types of live rock and the amount needed of a particular type should always be checked. Second the rock has to be cleaned as indicated above and in this period the rock lays quietly in seawater without livestock. Therefore there isn’t any ammonia being generated to support the bacteria’s needs and the population could reduce. To counter this, dead organisms could be producing ammonia and it is possible, for a time anyway, that the bacterial count could increase. The clean rock then goes into sale tanks where often it lays without livestock. Again the bacteria population could be decreasing. If the rock lays in a sale tank for a long period the bacteria count could be seriously depleted. It is always worthwhile checking how long since the rock was cleaned. Even with this knowledge the adequacy of the filtration ability of the rock will be unknown, hence the slow stocking.

If a bad reading appears during stocking then stocking any further should be postponed until the reading is correct – in other words until the bacteria can handle the bio-load. If the stocking is nearly complete or fully so and a bad reading appears and does not correct, then it is possible that there is a seawater circulation problem. If a check of the circulation pumps shows no problem then it is probable that the amount of rock is insufficient for the bio-load. Rock as desired should be purchased and introduced and a close watch on seawater test readings maintained. Always ensure that there is adequate seawater circulation when the new rock is introduced and of course that it is stable.

The maximum stocking level relevant to the net gallonage of the display aquarium should never be exceeded.

Generally, with canister and live rock filtration, it’s more likely to meet a problem with a fish only system than a reef one, all things being equal. Why is this? Fish present a higher bio-load to the bacteria than say corals. In a fish only system there are usually many fish for the size of aquarium, and they are all of course fed regularly. In a reef system, as said, the corals present a much lower bio-load and if there are fish present they are often smaller and should be less in number.

It’s not likely that serious problems will appear in a new aquarium system provided the aquarist prepares the system for the bio-load it will contain, that is fish only, a mixed reef system, or corals only. The new aquarist should always display patience, harder to do than might be thought. In a complete system a sudden problem is unlikely if maintenance is properly applied as anything untoward will become apparent in good time, particularly as the aquarist will have gained experience and understand the system thoroughly.

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.

---

Conversions

Here are a few conversions which could be useful to someone, you never know. The ones shown are those that could be applicable to aquarists, maybe!

To find volume.

Multiply length by breadth by height. (If finding the water space volume of an aquarium it is more accurate to measure from the water level. It must also be remembered that volume will be taken up by rocks and sand.)
Cubic inches to cubic centimeters – multiply by 16.3871
Cubic feet to cubic meters – multiply by 0.0283
Cubic centimeters to cubic inches – multiply by 0.061
Cubic meters to cubic feet  multiply by 35.315

Converting Centigrade to Fahrenheit.

C                         F
24                        75.2
25                        77 (the temperature many aquarists use)
26                        78.8
27                        80.6

Length.

(10 millimeters = 1 centimeter)
(1 inch = 2.5 centimeters)
Inches to millimeters – multiply by 25.4
Feet to meters – multiply by 0.3048
Millimeters to inches – multiply by 0.0394
Meters to feet – multiply by 3.2808

Area.

To find area multiply length by width.
Square inches to square centimeters – multiply by 6.4516
Square feet to square meters – multiply by 0.0929
Square centimeters to square inches – multiply by 0.155
Square meters to square feet – multiply by 10.764

Capacity.

UK fluid ounces to liters – multiply by 0.0284
US fluid ounces to liters – multiply by 0.0296
UK pints to liters – multiply by 0.5682
US pints to liters – multiply by 0.4732
UK gallons to liters – multiply by 4.546
US gallons to liters – multiply by 3.7854
Liters to UK fluid ounces – multiply by 35.1961
Liters to US fluid ounces – multiply by 33.8150
Liters to UK pints – multiply by 1.7598
Liters to US pints – multiply by 2.1134
Liters to UK gallons – multiply by 0.2199
Liters to US gallons – multiply by 0.2642

Weight.

Ounces to grams – multiply by 28.3495
Pounds to kilograms – multiply by 0.4536
Grams to ounces – multiply by 0.0353
Kilograms to pounds – multiply by 2.2046

(Reference: The Chambers Dictionary)

---

It Takes Time

Any experienced aquarist can understand why a newcomer to the hobby really wants to see some livestock in their aquarium, because those aquarists have been through the same process.

Doing things properly is a patience tester. This isn’t a bad thing because patience is at or very near top of the list of attributes that are very advantageous to a marine aquarist. It starts from the word go. First there is the question of the aquarium size and position and also perhaps a bit of diplomacy with the other half. Then there is the question of equipment and its cost, perhaps when the equipment list was complete and also running costs checked, mainly electricity, the aquarium needed to be downsized a little (in itself highly commendable if cost is a question, better to find out early). Collecting the equipment could have taken a considerable period, relieved from time to time by the excitement of opening another box.

Then the aquarium and equipment are all together. Great, off then!  Oh no, there it goes again, slow down, use patience. This is at the stage of livestock of course. The aquarist is well aware of what system it will be, usually fish only or mixed reef (there are some coral only systems about). Having done the research the reason for slowness in stocking becomes clear: the bio-filter. This is the life support for all the life within the aquarium. Without this support it wouldn’t be long before trouble struck, probably with tragic consequences.

The aquarist could be using live rock which is supplied ready for use, or cured (it can be supplied uncured leaving preparation to the aquarist, but the normal is cured). This live rock contains the bacteria necessary for dealing with toxins, namely ammonia and nitrite. These two toxins are deadly and the only acceptable level is ‘undetectable’ or zero. (Live rock should also be able to deal with nitrate within reason, but nitrate is not a toxin in the sense that ammonia and nitrite is.)

Or perhaps the aquarist has chosen a canister filter(s) to provide the bio service. This is fine, though it needs to be remembered that nitrate will be produced by this system and not removed. There aren’t any bacteria present in the canister filter at the beginning, they need to be kick-started. This can be achieved in several ways, though the best is using commercial maturation fluid and following directions.

So the stage is set. Whether it is a ‘matured’ canister filter or live rock, the aquarium should not be fully stocked.

In the case of the canister filter the maturation is primary. There is a bacterial presence to deal with ammonia and nitrite but the bacteria are new and probably few in number. It takes time for them to build and adjust to the full aquarium load. Placing a full aquarium load (or bio-load) would overpower the abilities of the bacteria to cope and disaster would follow. The bacteria would increase because of the high presence of toxins but not fast enough.

What of live rock? This is purchased hopefully with bacteria present. It is fairly certain that bacteria will be present but are there enough to deal with the full bio-load? It must be said that there could be, if the live rock has just been cured and is new for sale. Even then it isn’t certain though. Also, what if the live rock had been in the ‘for sale’ tank for a considerable period, as much of it is? All life needs food and this includes bacteria. If the rock has simply been sitting in a tank then the bacterial count could drop and be quite low.

So we’re back to the beginning, with the words patience and slow. With both live rock and canister filtration, stocking particularly with fish should be slow. This enables the bacteria that are present to have a chance of dealing with toxins which of course is good for the fish and the aquarist. Failure at such an early stage is not pleasant. As time progresses and the bio-load increases the bacteria populations also increase to keep pace and have a good chance of achieving this if stocking is slow. Eventually full stocking is reached and the bacteria then settle down to handling a more or less level load. Once this stage is reached and about three months have elapsed then the bio-filtration can be considered to be stable.

During the stocking period regular testing is required to ensure the bio-filtration is coping. This is easily achieved as ammonia and nitrite tests will hopefully show zero for both. If any reading does appear further stocking should cease and close control on feeding is needed. The readings should disappear and after a week or so of zero readings cautious further stocking can proceed.

During the stocking period routine seawater changes should be completed, these changes continue for the life of the aquarium. The guideline amount to change is 10% of the net seawater gallonage per week. This amount could be flexed once the aquarist has some experience and knows the traits of the aquarium, such as nitrate increase if any.

So what does the word ‘slow’ generally mean in relation to stocking? There are varying opinions though quite often the advice is to ‘stock slowly’ and nothing else, which isn’t particularly helpful.

Corals present a quite low bio-load in the aquarium and it is considered general good practice initially to sparsely populate the reef with the desired corals, which means they are spaced well apart. Later when it is apparent there is space available more could be added. It also gives time for the aquarist to see the extent of expansion that many corals exhibit. Those that do expand, and also those that don’t, grow. Corals of differing types should not touch. A reef that looks overcrowded probably is.

Fish present the biggest load for the bio-filtration to process. When a fish is introduced, feeding also needs to start, so the work of the bio-filtration really begins. The aquarist should have done research on the fish and know their habits and potential final size. It is good practice to put more timid or peaceable fish in earlier than robust and/or more aggressive types.

It cannot really be stated that an additional fish could be placed in the aquarium after every X period. The size of the fish needs to be considered. If a small fish is placed in the aquarium, then of course the bio-load will increase. After a period (see below), if all is well with seawater tests, then a further fish could be added. This also has the advantage that if the initial fish is timid then it has time to settle and become confident in its new home. The next fish could well be a small one too, so the same applies. A further fish could well be larger so it is good practice to increase the time allowed before any further addition, as the larger the fish the bigger the load it places on the bio-filtration. If the fish is an inch larger, allow an extra week. Proceed in this way keeping a close eye on seawater conditions and feeding carefully (meaning minimize excess) and all should be well.

There is a guideline for time periods between fish additions. This is general and not intended to be rigid in any way, particularly if an aquarist is not sure if all is well. In that case, wait! The general guideline is ‘a week an inch’. So if that is followed a two inch fish would require two weeks before another fish is introduced. If the next fish has a length of three inches then a three week period is required, and so on. The fish length excludes the tail. I’m not aware of any scientific evidence supporting this guideline, but it is sensible and works.

If the marine system has been well thought out, once the seawater has been placed into it and livestock is introduced it is the birth of a new mini aquatic world. Everything should be in balance as far as possible. The lighting should suit the corals, the corals should be properly spaced with sufficient seawater movement and the fish should be mutually compatible and suited to the system design, be that fish only or reef. Supporting the aquarium life is the bio-filtration which is absolutely essential.

The foundation for future success is current practice. Give Mother Nature’s bacteria time and they’ll do the job.

---

My Lovely Algae

Algae to an aquarist often mean trouble. It is one of the continuing ‘don’t wants’ of the aquarium. Hair algae, slime algae, yuk, no thanks! Then there’s the algae that’s purposely grown in a sump to aid filtration, usually Caulerpa.

The algae referred to here is none of the ‘horribles’, or Caulerpa, but the ‘reefy’ encrusting algae that is welcome, by me anyway.

At first when the aquarium started I used to keep all four side glasses clean. A considerable time later I noticed that encrusting algae had taken hold in a back corner. A closer look showed that it seemed decorative and welcome, so the algae’s impending doom with a scraper was averted. One end of the aquarium was not cleaned at all; it was left to its own devices. The glass turned green, the usual stuff, but despite twitching with the urge to clean it off, it was left alone. Over a few weeks it gradually turned dark.

I thought about this for a while, and then increased the alkalinity of the seawater from 2.5 meq/L to 4.0 meq/L. The reason for this action was that it had been anecdotally reported that bad algae grew poorly with higher alkalinity, but encrusting decorative algae does better. Having done this I monitored the corals carefully but nothing untoward occurred.

As time progressed the glass that had been left turned into dark, medium and light green patches. It also developed lots of tiny white pimples on it. It looked great.

Having obtained reassurance by this ‘experiment’, I left the back glass alone and just kept the front and one end glass clean. This was probably going to happen anyway as the corals were larger and getting to some areas of the glass had become difficult. The algae continued to develop and then covered the stated glass panels completely. The aquarium looks really great with this natural decoration in place. The original blue of the back glass can no longer be seen.

The alkalinity level has been maintained at 4.0 meq/L for years and the encrusting algae do seem to appreciate it.

I did note that algae over an area of about 2 square inches had come away from the glass and fallen down; it could be seen on a rock. The glass where it had been was clean. The fallen alga was quite thick, about 1/8 of an inch, so I assumed it had simply lost adhesion, glass is hard and smooth. Sure enough, the clean area was soon being taken over and is now once again covered.

Something else I have noted is that tiny shrimps, similar to the ones that scurry over the rocks and sand at night, take refuge behind some areas of the algae. Close inspection shows that the algae appears to be slightly loose in place – I wonder if the beasties have burrowed their way in or simply taken advantage.

Over time one or two additional patches of encrusting algae have come away and are growing back. Taking a photograph of the algae is difficult as corals tend to get in the way, however I did find one area that is reasonably open and used that. The patches on the left can be seen, in process of re-covering. Original algae can also be seen. Incidentally, the attached ‘leafy’ algae that can also be seen aren’t what I’m talking about, but are also very decorative. It is also very friendly in that if any does grow where it isn’t wanted the whole ‘leaf’ easily comes away for removal.

Algae can be the aquarist’s friend, adding a natural decorative background and increasing the overall attractiveness of the aquarium.

---

Supplementation

It is more likely that the reef aquarist will be involved in supplementation, though this is not exclusively so.

In order to achieve a successful marine aquarium of any type seawater quality is very important. Another way of putting it is that for the livestock to thrive the seawater has to meet their needs. Seawater parameters also need to be stable.

The question of salt can be squeezed in here – is this supplementation? Well, perhaps not in the strict sense but anyway… The general practice in the hobby is to measure salt by checking specific gravity (SG) with a hydrometer. The usual range is 1.022 to 1.025 for a fish only system, and 1.024 or 1.025 for a reef. SG has a habit of reducing over time and this is because of salt creep etc. The aquarist no doubt keeps the seawater level topped up with freshwater (preferably reverse osmosis) and checks the SG weekly. If the SG has reduced then it is a simple matter to increase the amount of dry salt that is added for the next routine seawater change.

Some aquarists supplement general minor trace elements. This is done because these trace elements, or some of them, are probably used by livestock and are also removed by protein skimming and activated carbon. Generally, a marine aquarium should not be without a protein skimmer and so this one negative has to be put up with. Similarly there could be a case for the use of activated carbon, though its continuous use is not usually necessary. Supplementing trace elements is a hit and miss affair, the aquarist usually goes by the instructions on the bottle relative to the net gallonage of the system. There doesn’t seem to be any harm done by this, though it generally contravenes the advice ‘Don’t add anything that can’t be tested for’. The aquarist should be aware of the condition of the seawater. A better way of dealing with general trace elements, in my opinion anyway, is to carry out routine seawater changes. The new seawater will contain trace elements and though those lost may not be totally replaced, they will be at least partially and this seems to be sufficient. I have relied on routine seawater changes in this way for years and heavily stocked coral reefs have not suffered.

What is the major supplement used? A fair guess would be calcium particularly with hard coral reefs, as these SPS coral types (SPS = small polyp stony) demand good calcium levels. The usual level maintained for a hard coral reef is from 420ppm (parts per million) to 450ppm, though some aquarists maintain levels as high as 480ppm. Soft coral reefs are fine as low as 400ppm though perhaps 420ppm is better. The aquarist, if testing is regularly done and a note of calcium presence is made, will be able to see the trend. The trend is down and over a period of time the loss can be seen. This enables the aquarist to supplement reasonably accurately. There are two major ways to supplement, the first being the commercially available bottle and the second automation. Which is chosen depends on the calcium demand and the size of the aquarium. In a soft coral aquarium for example, particularly if the aquarium is not large, a commercial application should suffice if routine seawater changes alone don’t. The supplement is added to the seawater in accordance with the manufacturer’s recommendations and in a quantity relevant to the demand. The procedure is very straightforward. The second way is to automate the supplementation by using for example a calcium reactor. This makes the process continuous and probably more favourable as the ‘ups and downs’ in the calcium level are less. Some time has to be spent in very carefully adjusting the seawater drip rate and also ensuring that gas injection is correct. The other requirement is to ensure that the calcium rich media is still present in enough usable quantity.

Whether the calcium addition in manual or automated the need to test is not removed. If the aquarist can see a repetition of the calcium requirement because a notebook has been used to jot down test results over time, then testing can be reduced in frequency¸ but nevertheless still needs to be done.

Another measure that needs to be known particularly with a reef system is alkalinity. Alkalinity is the measure of how much bicarbonate and to a lesser extent carbonate is present in the seawater providing resistance to downward changes in pH. It is sometimes called carbonate hardness or buffer capacity. A complete description of alkalinity will not be gone into, but from the foregoing it can be seen that it is important, the pH of seawater needs to be stable and in the correct range. So the reef aquarist needs to test and note the reading. Again, the trend for alkalinity in an aquarium is downward. Routine seawater changes will assist in the maintenance of the alkalinity level, but supplementation is often also required. Natural seawater has an alkalinity level of around 2.5meq/L. (Don’t worry about the unit measure of alkalinity, test kits give tables and usually conversions to other measures. The unit meq/L is only being used for demonstration. The measure often used otherwise is dKH, and to obtain this simply multiply the meq/L figure by 2.8.) The seas and oceans have vast reserves but in the comparatively diminutive aquarium with a relatively higher bio load it is usual to maintain a higher alkalinity level of between 3 to 4.5meq/L, though 4.0meq/L seems a good measure. Again, if tests have been completed over time and a note made the trend of the aquarium can be seen, permitting the aquarist to know how much needs to be supplemented. Supplementation can be manual using additives that are commercially available, a very straightforward process. Another way is to use sodium bicarbonate (baking soda), use about one teaspoonful per 25 gallons of seawater and add to the sump or another area away from corals (mix the powder in some seawater before adding it). If the aquarist uses a two part alkalinity/calcium additive or uses Kalkwasser there could be no need for further alkalinity supplementation. Tests will give the answer.

There are other supplements available, but there is more controversy over these. For example, iodine is said to be particularly beneficial to soft corals and of benefit to all types. Iodine is available commercially and should be added strictly according to the instructions. Only a small amount is needed as required iodine levels are very low. As far as I am aware there isn’t any scientific proof that iodine addition is of any great benefit to the reef livestock, though there are many aquarists who do add it and state that it is of use. With this state of affairs it would seem reasonable to add it, remembering that some will be gained from routine seawater changes. Iodine can be tested for.

Magnesium could be another addition used by the aquarist. Sometimes the dry salt mix itself falls short of the desired level though this is probably uncommon. A check of the level present in the aquarium seawater should be made and a decision based on that.

There are other little bottles that can sometimes be found in aquarium stores, such as molybdenum, bromide, fluoride and vanadium. Sometimes the bottle could contain more than one. Whether there is a real need for supplements of this type is a basis for argument. All I can say is there are many aquarists with lovely successful aquariums that have never used them. Also, routine seawater changes will replace necessary elements at least to an extent.

The main point that needs to be remembered is that ‘magic bottles’ do not bring success, the design and maintenance of the aquarium is the main foundation for this. Maintenance includes testing of the seawater and ensuring that any known necessary elements are present in amounts that are required by the livestock. Overdosing can be very detrimental, so the aquarist has to know the additive quantity actually required without guesswork, which means seawater testing. This testing can be reduced in time if the aquarist keeps a note of test results and aquarium trends can be seen, however testing still needs to be done.

Another point worth mentioning is that if any desired level is found to be markedly deficient supplementing to regain the correct level should not be done quickly. Stability is a requirement already mentioned, so if a larger change is required it should be done slowly in small steps.

‘High quality seawater’ is generally accepted as the number one requirement in any type of marine system. This high quality is sometimes simply interpreted as a lack of nitrates and phosphates which is correct up to a point. Particularly in a reef system, the presence of elements in sufficient amounts to meet the needs of livestock is also important.

---

How Gallonage Matters

No matter how big or small an aquarium is they all have a gallonage which is often stated in the manufacturer’s documents. Some aquariums are of a standard size and are known as a ‘fifty’ or whatever.

The gallonage quoted in the aquarium name or manufacturer’s documents is with it empty, it has to be this way as of course the manufacturer has no idea of what use the aquarium will be put to and what will be inside it.

As far as the marine hobby is concerned, the quoted gross gallonage can be ignored, it is irrelevant. What is of interest is the net gallonage, the amount of seawater the aquarium can hold once all the decorative whatnots are installed. In the case of both a fish only and reef aquarium, whether live or inert rock is being used doesn’t matter; it is the amount that is installed that does. In the first place, if live rock is being used there must be enough to provide adequate bio-filtration for the full bio load. Secondly, the more there is of either rock type the less the seawater gallonage will be.

If the aquarist decides to use a DSB (deep sand bed) or plenum then this will again reduce the seawater gallonage. A decorative sand bed is not as deep but still accounts for lost seawater space.

So it is important that the aquarist is aware of the net gallonage of the aquarium. Having a sump has advantages and one of these is that the net gallonage is increased.

Calculating the net gallonage could be a hit and miss affair. Probably the most accurate way is for the aquarist to measure the prepared seawater as it goes into the aquarium on the first fill. However, many aquarists mix the initial seawater in the aquarium, but nevertheless a note could be made of the amount that goes in. If any of this first fill is eventually removed because of overfill it needs to be deducted of course. There are helpful gallonage calculators on some marine forums for those who did not measure the ingoing seawater, though accuracy will be lower.

Both the reef and fish only aquarium rely on net gallonage for stocking levels. This is for fish; corals present a much lower bio load. The reef aquarium carries less fish than a fish only system which gives regard to necessary seawater quality. With both systems seawater quality is the number one requirement – how can the aquarist stock correctly if the net gallonage is not known?

When calculating stocking levels for whatever system, the sump seawater should be ignored. The seawater in the sump is not available to the fish and should be viewed as a quality enhancement advantage.

Stocking to the gross gallonage of the display aquarium, or to an overestimated net gallonage could lead to trouble. The aquarium could be and is likely to be overstocked. If there are too many fish there is greater pressure on the seawater quality. In addition it creates more work for the bio-filtration. Further, if there was a temperature increase there could be oxygen problems. The fish obviously require sufficient oxygen, and so does the bio-filter, or rather all the oxygen hungry bacteria in it. If there are problems with the bio-filtration then real trouble could begin.

Also, overstocking can mean overcrowding. Fish will argue and even fight over the right to territory, some more than others. This could lead to fish not eating properly because of stress. On the wild reef fish have plenty of hiding places and in addition if they need to retreat there is plenty of space to do so. Within the strict confines of an aquarium where does a fleeing fish go?

So it is certainly to the advantage of the aquarist and his/her future enjoyment of the hobby to go through a careful initial procedure. This includes research into compatibility with tank mates and aquarium type of course, but should also consider the space that is going to be available. During reef or aquascape construction the aquarist should give full regard to supplying sufficient homes for the number of fish it is intended to keep, many commonly used rocks are helpful with this because they are of very irregular shapes. It will pay off as fish that are settled and secure will be healthy and show the colours that nature intended.

---

Next Page »