Non-photosynthetic coldwater corals are definitely not for beginners

Photo by: Steve Weast

Blame my holiday, but I’ve only just caught up with the latest issue of Advanced Aquarist, and its article on coldwater marine aquariums.

It’s a pretty good read, particularly if you want to know more about the physics of heat and light that leads to such different coastal habitats in the chilly North compared to that enjoyed near the equator:

Due to differences in seawater density (the result of different seawater temperatures), sea level is approximately 8 cm (3 in) higher at the equator than it is at the poles. The resulting slope is sufficiently steep enough to move enormous amounts of water to the poles. Cooled, denser polar waters sink and creep back to the tropics from the deep.

Another, more complex, system of currents is driven by the planetary wind system. At the equator, moist, heated air rises and drifts toward the poles. Much of the moisture is lost by rain as the air cools en rout. At about 30° north and south, this drier, cooler, denser air sinks. It is then reheated and rehydrated, it rises again and flows to about 60° north and south were it produces yet another high-precipitation area. These much cooler winds flow into the polar regions.

There’s lots more where that came from, as well as a discussion about whether coldwater marine keeping could take up some of the demand currently exerted on tropical reefing, and what the consequences might be.

Keeping coldwater marine creatures

While the article touches on one big problem – the limited supply of livestock – there’s not much else about the practicalities of coldwater marine fishkeeping.

I’ve kept coldwater marines here in the UK, and by far the biggest problem is keeping the tank cool.

It’s often not enough to simply use a chiller, as you would with a tropical reef system. With a reef tank you’re only looking to lower the temperature a few degrees to keep it around the 24°C range, whereas with a coldwater tank you want to go much cooler for long-term success.

If you can, it’s therefore best to head underground into a cellar or basement to setup your coldwater tank. Failing, that a naturally chilly North-facing room that’s cut off from the rest of your house might work.

Once you’ve got a cool tank, use low wattage pumps like streams and try to keep heat out of the aquarium. The Ecotech pumps, which mount the hot element outside of the tank, would be ideal.

Lighting isn’t a problem traditionally for coldwater tanks, but that’s because few of us have tried to keep many seaweeds. As the Advanced Aquarist author says, a proper temperate habitat would be dominated by kelp and the like. That said, you’d probably get away with T5s or better yet cool running LEDs in shallow tanks.

Use a big tank if possible, partly because coldwater animals really like to eat, and also their oxygen requirements are higher so if you want to keep multiple fish and the like, a bigger tank is the way to go.

Filtration is best achieved using the old marine system stalwarts of undergravel filters (possibly reverse flow) and/or an external wet-dry filter.

Use a big skimmer, since your tank will generate lots of waste. I’d consider exploring an algae filter for nutrient export, though I don’t know if anyone has done that yet.

Want to know more? I looked at Jon Olav Bjørndal’s Scandanavian coldwater set-up in my great aquarium blogs post. It’s well worth checking out. Steve Weast’s coldwater system, as cited in the Advanced Aquarist text, is also an inspiring read.

Responsible note regarding coldwater corals

I know I probably bore some readers banging on about conservation, but nevertheless I have to say I hope keeping coldwater corals doesn’t take off until we understand a lot more about them, particularly their care and growth rates, and ideally propagation.

Coldwater corals are generally solitary or form far smaller colonies than their tropical brethren, require feeding with planktonic organisms, and as I understand it grow very slowly. A few experienced fishkeepers like Steve Weast developing techniques is one thing, but hordes of us suddenly donning wetsuits to plunder a limited supply would be bad news.

Besides, there’s plenty of other cool coldwater creatures to keep, including various seaweeds, molluscs, crustaceans, worms and, of course, fish!

Further reading:

1. Coldwater marine tank in Norway
2. CO2 in planted aquariums
3. Soft coral tank shines in November’s Reefkeeping magazine

Bommies often occur in the semi-sandy, semi-rocky back reef areas known as patch reefs.

If I was setting up the larger tank my heart would love but my head resists (because I’ll very likely be moving house soon) then I’d definitely create a patch reef habitat.

One of the nicest tanks I’ve ever seen was basically a patch reef:

This patch reef tank did service as a frag nursery

(More details here)

That tank is not exactly a looker, compared to the spectacular reefs you see winning Tank of the Month over at Reef Central.

But what I love about it is it’s naturalistic:

• Loose groupings of assorted small corals
• Little stands of macroalgae
• Small amount of living rock placed directly into the sand

All these elements together evoke the No Man’s Land of a patch reef.

Here’s a real image to compare it with:

Two angelfish flit over a Caribbean patch reef

(Image from USGS)

The closest most of us come to this is if we set up a lagoonal-style aquarium, perhaps to keep LPS corals or certain soft corals.

Yet hard corals are just as well-suited to this habitat.

Certainly hard corals can grow perpendicular to a reef wall like in a typical reef tank, but if you were going to generalize you’d say they more often grow upwards from a horizontal plane, whether they be flattish table Acropora corals or massive boulders like Favia.

Forcing them to grow up and away from living rock like we often do in our aquariums isn’t exactly unnatural – coral can and does grow wherever it is able – but it’s not typical, either.

Setting up a patch reef tank

If I was setting up a patch reef aquarium, I’d want to use a six-foot or longer tank, with at least two-foot from front-to-back.

Live rock would be scattered on the surface of a sandy substrate, occasionally buried deeper into the fairly fine white sand, and rising in one or two places to form mini-bommies.

Tangs and similar fish would have an unusual amount of space to range over the rock and coral, since their movement would be unimpeded by the structures of a typical reef aquarium.

It would also be fairly easy to create currents in such a tank, again due to the lack of rock walls.

Unfortunately for me (but not for you, if you feel inspired and have a spare six-foot aquarium) I think it’d be a mistake to set up a large tank with a deep sandbed when I’m very likely to have to move house soon.

Could I create a patch reef effect in a smaller aquarium?

I’m not sure.

There are some nice examples of sand-based nanos floating around the Internet, such as the little 20-gallon tank below which I think is lovely:

This stunning nano is on the line between patch reef and grotto.

(Full details here).

While the tiny Zoanthids and other corals scattered across the sandy bed evoke a messy patch reef habitat, there’s no doubt this little nano gets at least as much of its impact from the rocky wall towards the back of the tank (as well as the clever lighting).

I do think the undulating substrate and the choice of small specimens suggests it’s not impossible to create the illusion of a patch reef in a small tank.

But there’s a clear risk of it looking like a holding tank at your local fish store, if you lack the artistic vision of that reefer.

Possible inhabitants of a nano patch reef

Corals and sessile invertebrates

Almost any corals could be appropriate in a patch reef tank, since patch reefs frequently play home to all kinds of juvenile sessile invertebrates.

It’s through establishing a foothold in such places and putting down layers of growth that corals eventually build new reef areas.

In practical terms for our nano aquarium, smaller soft corals and hardier, more encrusting hard corals, as well as frags of LPS would be best.

Anything that grows big or quickly will soon throw the tank out of scale.

Appropriate fish species

Fish choice would unfortunately be limited by the size of the nano tank.

In particular the tangs, surgeonfish, butterflies, parrotfish and larger angels that would benefit so much from the open space of a patch reef aquarium would be completely ruled out on size grounds.

Equally, many of the fish that are best suited to life in smaller aquaria also feel most at home in dense rocky environments – they don’t wander far, which is what makes them suitable for small tanks, but they also like a complicated territory to feel secure.

Small Centropyge angels are one species that would not be suitable for this reason.

The best choice might be one or two small gobies, and perhaps a few Chromis damsels.

Neither fish will add much ecologically to the tank – they won’t graze algae, for instance – but they will fulfil an aesthetic function.

Other invertebrates

Reef snails like Astrea would be definite additions to the tank. I’d probably add a small hermit or two, for all their foibles.

Plant life

Although not a full-on lagoonal habitat, patch reefs often feature stands of macro algae, and I’d look to include some slower-growing types in any patch reef habitat.

Environmental factors and equipment

The environmental requirements and equipment needed would be very similar to that detailed for the coral bommie aquarium earlier, so refer back to that post for more information.

Bommies are often located in patch reefs.

In terms of flow, you could probably get away with less powerful pumps, especially while the tank was relatively young, as there would be a very clear run for the water without coral or rock structures to push back.

A sandbed is surely a must for a patch reef tank, not least for aesthetics, which will present some constraints to the current, also.

In terms of lighting the patch reef, a longer shallow tank could use less intensive lighting.

T5s would do the trick in sufficient numbers. For a nano tank patch reef, I’d even consider trying out LED strips.

There are many ways to filter such a tank, but again there would be no need to do anything very different from the bommie nano tank.

Using algae / mud-based filtration and encouraging an extensive sandbed fauna would be an option, but it wouldn’t be as compelling as if you were creating a lagoonal habitat with eelgrass, mangroves, filter-feeders and seahorses, say.

Final thoughts on the nano patch reef

I’m not finding this idea as compelling as the nano bommie tank.

I’d love to set up a long, flat and shallow tank without live rock walls, but as I said above I’d hope to enjoy algae-eating herbivores such as tangs gliding above it.

In a nano tank, the sense of scale would be lost, while the growth of most specimens would soon give the appearance more of a grotto.

I think a 48×18x18” tank is the minimum size to attempt a patch reef habitat, and ideally it’d be a couple of feet longer.

For me, that must wait until I’m in a more permanent home, but please let me know if you’ve taken this biotype further in the comments below!

Further reading:

1. Creating a coral bommie reef tank in a small cube aquarium
2. Nano reef tanks to die for every month
3. Setting up a reef tank

Surprisingly, there's no trends in SPS plugs yet to match the frag fashions!

Glassbox-Design spotted this LiveAquaria.com guide to the plugs used by different companies for their aquacultured corals.

Forgotten where an old frag came from? Carry your laptop down to your reef tank and compare and contrast the plugs on the site with the ones in your tank.

The coral frags plug guide might also prove useful for those trying to avoid corals ‘chop-shopped’ and passed off as aqua-cultured specimens.

Further reading:

1. Fragging leather coral
2. How to keep bubble coral
3. Should fraggers who colour corals with photoshop be named and shamed?

Bommies are outcrops of coral or rock on the natural reef

Regular readers may remember I’m considering setting up a couple of small reef aquariums, as a stop gap before I move house again.

One possibility I’m mulling over is a coral bommie-themed, hard coral dominated aquarium.

Coral bommies are outcrops of rock and coral. They emerge from flatter areas of coral and rock, or sit in sandy areas in the back reef.

I’ve an old 35-gallon Aqua Medic Chromis tank that I could use to create a small bommie-themed aquarium.

The idea would be to have a central pillar of rocks, completely exposed on all four sides to the current, with sessile lifeforms growing up and outwards from this central column.

This would be instead of the usual nano set-up, which is to cram the tank with rocks and coral due to the inevitable conflict between a small tank and greedy eyes at the Local Fish Store!

Bommie aquarium inspirations

I really admire a couple of gorgeous bommie-style aquariums on Nano-Reef.com:

• 20-inch SPS-dominated cube by member ezcompany
• 17-inch SPS-dominated cube by member Bluebastion

Small tanks like this look far simpler to achieve than they really are, incidentally. In my experience it’s harder to keep a small tank ticking over than a large one, and it often seems almost as expensive!

In terms of the natural reefs, my library of coral books features a good few bommie pictures to inspire me, plus I’ve collected a few good images off the Internet via a Google image search for coral bommie pictures.

Inhabitants of the bommie aquarium

Corals and sessile invertebrates

Stony corals such as Acropora and Millepora growing up and out from the rock would dominate the aquascape.

Montipora and other encrusting or spreading corals could find a niche at lower levels, with certain compact (and non-invasive!) soft corals such as Zoanthids and Ricordea potentially tucked into the mix.

One or two Tridicna clams could find a home in the middle areas of the bommie, and I’d look to find a gap for a stand of a containable macro algae, too, such as the calcareous Halimeda, or maybe one of the red algae.

Keeping these animals in close proximity without too many turf wars would be a challenge.

Appropriate fish species

Photos of bommies always show very diverse fish populations.

• Small wrasse would be ideal, but I’d need to select species that don’t require a deep sand bed.

• Dottybacks and Anthias are frequently found in big shoals in this sort of environment, so they may be a good bet. The latter can be delicate, however.

• Damsels would do well and feel at home, especially as the coral grew out to provide more real estate for them. On the other hand, the tank wouldn’t offer much territory for these notoriously pugnacious fish.

• Clownfish would be fine, though I won’t be keeping anemones in this small tank. I’ve a soft spot for Sebae clownfish and haven’t kept them for years, so a pair would be high on my list.

• Certain dwarf angelfish do well in smaller tanks, and might help with algae.

• A goby or two could find niches, although some such as the Clown goby can pick at SPS.

In the wild bommies would be periodically grazed by passing tangs and surgeonfish, but I don’t think this tank is large enough to house one long-term.

Possibly if I came across a tiny regal or yellow tang I might add one, on the grounds I’ll be upgrading in future when I sort out my longer-term housing. If that plan was delayed, I’d pass the fish on. We’ll see.

Other invertebrates

Reef snails like Astrea would be definite additions to the tank.

I’d probably add a small hermit or two, for all their foibles. A small group of cleaner shrimps could lurk within the bommie core, and they’d be likely to produce larvae every couple of weeks, providing some useful live food to the tank.

Tank environment considerations

• The currents will need to be extremely fast and turbulent, preferably with a pulsed flow to send water surging across and around the central rocks.

• Lighting will need to be bright and centrally located.

• Calcium and other supplementation could initially be through two-part preparations. In the long-term I may need to add a calcium reactor or similar. But it might be avoidable in a small aquarium like this, even with the SPS growth.

I think I’d skip a sandbed in this tank; if I can move the water at the rate I’d like to then it will probably be blown about, although a slightly coarser bed is a possibility.

One reason I might add sand is that I don’t intend adding much live rock. With a lot of rock, the bommie effect is going to be diminished.

I’m currently thinking of hand selecting three or four pieces and placing them centrally, either secured to some supporting framework hidden within the rocks, or else sticking them together using an underwater epoxy. (Not great if I move house though!)

Much of the eventual structure and height will hopefully come from the growth of the hard corals.

In Part 2 I’ll look at the equipment issues for this bommie reef tank. Please do add any thoughts on this tank in the comments below, or subscribe to follow my coral bommie’s progress.

Further reading:

1. Creating a patch reef habitat in a nano aquarium
2. Soft coral tank shines in November’s Reefkeeping magazine
3. Reef Central Tank of the Month January 2008

I do feel a little guilty, since it’s basically fellow fishkeepers revealing their pain!

But I defy anyone who has ever kept a reef tank to say they’ve never felt as desperate as some of these posters.

Here’s the thread originator, craigg:

I’m having a moment tonight.

Really hate it, every single thing about it.

My sun coral zone collapsed for no reason. Sun corals being the single reason I didn’t strip my tank down fully and now I hate how I have redesigned it.

Damn I wish I had closed it down and smashed it up.

Keeping a reef tank is a special kind of frustrating pain. Like many other people, I’ve described it as my crack cocaine – it’s as expensive and time-consuming, if not as dangerous (unless you keep lionfish).

I’ve pulled out a few more choice quotes below.

You may feel better knowing you’re not alone!

StephanG:

yes i really can hate my tank at times, i hate the nitrates, etc also wish it was bigger and have been getting really annoyed at my maroon clown which has lately taken to trying to host in my Cataphillia and pushing corals about the tank

Cyrus:

I know what you mean – I’ve spent good money after bad this year. Changed the lighting set up a million times . At long last, this week thought I could just sit back and enjoy. Now I look at my tank and it just makes me angry. Don’t know why. Possibly ‘post -tank set up depression’ .

Maestro:

I honestly remember times when I’d walk into the dining room where the tank was and I just couldn’t as I walked past, it was just so annoying after all the money and time you spend.

Tontikki:

Sometimes when other things in life go wrong and i come home and see my tank and it makes me think what’s the point of having it, and then i want to get rid of it, but then i’d notice the coral grown a little bit, fish have eggs etc and i realise they are happy in there, and it changes the picture

Holidays are the worst for a reefer…Has anyone been on holiday and not worried about something bad waiting for them when they return?

The other time I really truly detested it was the time when I had a mystery wrasse which ate every other fish in the tank in the space of two days (pair of helfrichis fire fish and pair of yasha gobies) then jumped itself the next day.

Probably the most unrewarding 300 quid I’ll ever spend!

If you didnt laugh you’d cry

Further reading:

1. Soft coral tank shines in November’s Reefkeeping magazine
2. Global warming turning oceans acidic ten times faster than thought
3. Saving a starving sun coral

A healthy reef tank grows out of good decisions (Image by: JSC )

Consciously or not, setting up a reef tank means making many different decisions to create the sort of aquarium you desire.

Things to think about when setting up a reef tank include:

• Environment Such as temperature, salinity and other water parameters, currents in the aquarium and the tank furnishings

• Equipment What artificial aids will you use to create such an environment in your aquarium?

• Animals and plants The inhabitants of a reef tank are not simply exhibits – they are a dynamic part of an ecosystem

• Aesthetics Many aquarium fish will happily live and breed in bare glass tanks with white PVC pipes for shelter, but would you want that in your living room?

• Budget and space Only AquaDaily readers who work for zoos and public aquariums can ignore the pragmatic limits on their ambitions. (I dare say that much-wanted blue whale exhibit will also go on hold, even for zookeepers!)

• Personal quirks Most of us have fish or other creatures we’ll instinctively add to a new aquarium. Beyond that, some fishkeepers have a fetish for rare fish, or a desire to avoid artificial filtration. These sorts of quirks will further influence your choices.

Each of us will have our unique perspective on certain criteria, such as aesthetics. Some aquarists prefer very natural (or even random) looking environments in their tanks, for instance, while in contrast there’s a growing trend in stony coral reef tanks for a more stripped-back, ‘bonsai’ approach.

Other criteria, such as the needs of your animals, are not a matter of personal choice but of animal biology.

While most fish, invertebrates and plants have a range of conditions they’ll tolerate, staying within those limits should be considered non-negotiable for the health of the creatures in your care.

Decide what you want before setting up a reef tank

Any approach that suits your tastes and budget is absolutely fine, provided it keeps your animals content and healthy; you don’t have to follow the latest fashion.

Too often though, new aquarists don’t think about these issues at all before setting up a tank.

At best, decisions are instead made on-the-fly as the tank evolves. At worst, the aquarist never gets to grips with what aquarium he or she has created, which can lead to a deteriorating tank conditions and the death of the tank’s inhabitants.

The freshwater community fish many of us enter the hobby keeping will tolerate a fair amount of indecision as the new fishkeeper finds his feet.

Marine fish and invertebrates are far less forgiving. Thought put into a new reef tank ahead of its inception will repay you tenfold in problems that never materialize. (You’ll still see enough problems to keep you busy, don’t worry… )

My next reef tank

I’ve been thinking about these issues, since I’m hoping to set up a new reef tank soon, after 18 months without touching a drop of salt water.

The good news for new tank junkies is I intend to document my new tank’s progress here on AquaDaily!

When I last moved home, I had to sell all the inhabitants of my aquariums.

Family illness and career uncertainty (neither of which has entirely gone away) has further delayed the new tank. I rent an apartment, rather than own my own home, which brings yet more uncertainty to proceedings; moving house with a big tank at one month’s notice would not be pleasant.

But I’m finding life without a reef aquarium is hardly worth living, so some sort of new tank is required. (Okay, I exaggerate, but not by much!)

I therefore need to decide what kind of tank I want to create, and what resources I can devote to it.

Little or large reef tank?

I kept some small tanks when I moved that I could press into service, or I could buy a new bigger aquarium, fill it with rock and sand, and regret doing so at my leisure when it comes time to move.

Even typing these words makes me think it would be folly to build the new 300-gallon reef I dream of, only to have to strip it down in 18 months.

I think it’s more sensible to set up one or possibly two smaller aquariums.

Natural biotype tank

What I’d really like to do with my next ‘proper’ tank is create a more representative slice of a coral reef.

Many tanks full of living rock aren’t very natural, even when they avoid the old-fashioned rock wall look. You’d never see the hotpotch of different corals packed into one section of vertical reef like we typically include in our tanks. The inhabitants we choose is almost always driven by our tastes and aesthetic considerations ahead of their natural origins.

On the other hand, recreating some slices of the reef, such as the highly turbulent reef wall, undeniably limits your choice, especially with small aquariums – not so much a reef wall as a reef rockery. If you’ve several tanks, it’s less restricting to create tanks themed by biotype.

While I’m sure I’ll bend and break definitions like any other marine hobbyist, I want to at least aim for something you could imagine seeing in the ocean, so I’d like to decide on a biotype for my new aquarium.

Animal and plant compatibility

One huge advantage of having multiple aquariums, as opposed to a large, multi-zoned tank, is the opportunity to keep creatures that would be incompatible in a single tank.

For instance, nothing could be more natural to a back reef biotype than tangs and macroalgae or lionfish and damselfish, but you can’t keep such pairings in a small body of water, since the former will eat the latter!

Environmental constraints also play a role in limiting your stock choice, although knowing your animals can offset this to some extent.

For example, I’ve found mushroom corals and certain large-polyped stony corals do much better in less bright, more nutrient-rich systems.

In even a smaller aquarium you can get around the light issue – and similar preferences for water flow – by understanding exactly how light and currents are distributed in your tank, and placing your animals accordingly.

In this case, mushroom corals can be positioned towards the fringes of the tank, where they are also less likely to bother and sting SPS corals.

The preference for nutrient-rich water is an example of a parameter where it’s impossible to please all tank inhabitants, however.

Small-polyped reef building corals like Acropora are prettier (if not necessarily healthier) in water that’s very low in nutrients. Mushroom corals will survive and even grow in nutrient poor systems (especially if target fed) but I wouldn’t try keeping delicate LPS such as Goniapora in such tanks, let alone filter-feeding invertebrates such as fanworms.

For SPS I’d prefer a heavily-skimmed aquarium, while I’d rather keep filter-feeders and LPS in an algae-filtered natural tank.

Decision time approaches

I’ve three ideas for environments I’d like to explore. Each is a fairly obvious reef biotype, but on the small scale of tanks I’m talking about it won’t be possible to create more than one biotype per aquarium.

I’ll cover each biotype in posts over the next two weeks and add shortcuts below as I do so. Please do subscribe to follow my new reef tank!

Further reading:

1. Creating a coral bommie reef tank in a small cube aquarium
2. Video guide to setting up your first tropical fish tank
3. Reef Central Tank of the Month January 2008

If your tank is well-stocked and you feed your fish heavily then you may sometimes see ammonia spike up to 0.2 ppm temporarily, before rapidly subsiding.

Levels of ammonia up to 0.4 ppm or so can be tolerated by most marine fish for 2-3 days. Higher levels will kill some or all of them.

Consistent levels ammonia above 0.1ppm are a concern, and you should investigate and remedy such a situation without delay.

Causes of high ammonia readings

Ammonium is the first product of the nitrogen cycle, which means many problems in your tank are likely to manifest themselves first in an elevated ammonia reading.

Here are some of the  most common causes of a sudden spike:

1. The tank or filter is immature

Fish-only tanks filtered by trickle filters, undergravel filters or external power filters take months to mature. Even if you’ve chosen the right filter for your aquarium, it takes time for the bacterial population to expand and stabilise, not to mention all the other populations living on tank furniture, sand, and so on.

Equally, living rock will die back in a new reef aquarium before it begins to process waste efficiently.

If you introduce fish or other animals before the tank has cycled, you’ll see the ammonia level rise, threatening their lives.

This is why old-time marine fishkeepers used to start their tanks with tough specimens like damsels. Today chemical maturing products can play the same role.

After a few days the ammonia level will fall as the bacteria convert its into nitrite, and in turn into nitrate. If you’ve started with hardly fish or inverts, you may be lucky, but there’s not really a shortcut to speeding up the cycling process.

The same thing will also happen if you add too many new creatures to even a cycled and mature aquarium. Build up your collection slowly.

2. You’ve overfed your aquarium

Adding too much food to the aquarium at once will result in some lying around uneaten, which will swiftly start to break down into ammonia. This is even more pronounced in tanks without heavy protein skimming.

Stop feeding until the ammonia subsides (and the follow-up nitrite). Then feed more carefully in future.

3. Something big has died

In larger, mature aquariums it’s easy to lose a fish without noticing for a day or two, and often the tank can cope without an ammonia spike. But in smaller or newer aquariums, the death of almost any significant lifeform will quickly overwhelm the natural filtration capacity of your tank and cause a spike in ammonia.

Many tank crashes happen like this, particularly when an owner is on holiday. One fish dies and starts to decay, and the resulting ammonia and nitrite kills other fish, making the situation worse.

Be vigilant about checking your fish population every day.

4. The biological filter has been poisoned

Fish-only aquariums where medications are used directly can have their filtration systems compromised by accident.

Copper, which is used to treat whitespot and velvet in marine fishes, can easily damage a bacterial filter bed. Copper-resistant bacteria will in time evolve as treatment continues and the ammonia level will subside, but in the meantime your fish face sub-optimal water conditions as well as whatever disease ails them.

Reduce feeding and consider a big water change. If ammonia levels rise above 0.3 ppm, you’ll have to discontinue treatment.

Aquariums of all kinds can also be poisoned by external chemicals, such as carpet-cleaning fluids or paint fumes. Be extra careful if you’re using a protein skimmer, a trickle filter or if your tank is uncovered.

Some such poisons are biodegradable, others aren’t. Try using a Polyfilter or other resin to remove the poison, and monitor the ammonia level and your animals closely.

5. There’s been a power cut

In a power cut, pumps will fail, water circulation will cease, and animals will become stressed and potentially die, while filter bacteria will be killed off by a lack of oxygenated water.

Animal waste will no longer be broken down properly, while in submerged filters the nitrogen cycle can go into reverse, as anaerobic bacteria convert nitrate back into ammonia.

If you can, draw water through your filter every 30 minutes to keep it alive (by syphoning or similar). Also be glad you bought a battery airpump beforehand to keep water moving in your main tank.

With power cuts that last for over 12 hours, you may need to consider discarding external filters and replacing all the filter media in them.

This will obviously have devastating consequences for your aquarium inhabitants, particularly in tanks without living rock or sand beds, as waste will no longer be properly broken down. You will have to distribute fish to friends and local shops – assuming they didn’t also suffer in the power cut!

Large water changes, preferably from a reservoir of pre-made water, can reduce the ammonia level in proportion to the amount you replace but truly high levels of ammonia require you to remove the fish to another tank until it (and whatever caused it) is brought back under control. Otherwise, some or all your animals will die.

Further reading: Ammonia and the Reef Aquarium by Randy Holmes-Farley

Further reading:

1. Oxygen levels for fish and plants in a tropical aquarium
2. Could coldwater aquariums be the next big thing in marine fishkeeping?
3. Determining CO2 levels by testing the pH and KH of your aquarium

This maxima clam hybrid is looking really cross...

All you U.S. clam-lovers should head over to reefbuilders pronto, where they’re highlighting what they claim is a new clam hybrid.

reefbuilders says of the stunning hybrid clam, pictured above:

Although T. derasa and T. squamosa hybrids have been around for years, the T. maxima x crocea (T. ‘maxea‘) hybrids have just recently become available from captive hybridization on the farm. [...]

Not all Maxeas are created equal and there appears to be great variability in the appearance and vibrance of this new hybrid clam variety. The Maxeas are not too expensive, where a 2-3″ high grade T. maxima would sell at retail for $79, a similarly sized Maxea would probably retail for $99-$119.

Great news that it’s aquacultured. Giant clams have long been something you can put in your reef aquarium with a clear conscience, thanks to a thriving farming industry that’s built on the back of growing clams for food and reef replenishment.

In contrast, the coral side of the hobby has arguably taken a step back in recent years with the vogue for rare new LPS species from the wild, after years of great progress with SPS frags.

I’d like to see more effort put into sexual reproduction to create LPS offspring. (Indeed, I’d love to do it – donations for PhD funding welcome!)

Further reading:

1. How to keep bubble coral
2. Londoner grows coral in his own shed
3. Aquarists and fish trade must support conservation, says Michigan retailer

It's hard to believe this mature captive reef is less than four years old

Quick note to say the new issue of the online Reefkeeping magazine is out. And as always, the tank of the month is to die for.

In some ways it’s yet another in-wall, fish-room-behind-the-tank labour of love that tends to typify Reefkeeping’s Tank of the Month picks, but it has some unusual elements, especially the heavy emphasis on ceramic rockwork early on.

Owner John Ouverson says:

I know that a number of people had a lot of trouble with high pH because of Reef Ceramics; but after properly curing them, I never experienced any trouble. After a while, I started to run out of room for placing more corals, so I ended up adding a bunch of live rock to connect the pillars and the back wall.

In the end, the tank has a ton of room for coral placement and growth, and it has a very open feel.

Jon also has an unusual approach to freshwater top-off and water changes that’s worth other big tank owners reading up on. He has his own aquarium website, Shallow Reef, too.

Elsewhere, Reefkeeping features a profile of the Blue Spine Unicorn tang, and an article about fine tuning your weir to cope with higher water levels.

Go read it all in the new February 2009 issue of Reefkeeping.

Further reading:

1. August 2008 issue of Reefkeeping Magazine, with DIY Wavebox tutorial
2. Soft coral tank shines in November’s Reefkeeping magazine
3. Stunning conservatory-housed Tank of the Month at Reefkeeping magazine

The Debelius pygmy seahorse is less than one-inch tall

A flurry of new seahorse discoveries has culminated in this beautiful photo from National Geographic of the Debelius pygmy seahorse.

Like the other new discoveries, the Debelius seahorse is barely an inch tall. It is named after Helmut Debelius, the underwater photographer familiar to crusty old marine aquarists like me for his classic sealife books such as Armoured Knights of the Sea.

According to National Geographic’s Helen Scales (great name for an aquatic journalist!):

After initial sightings in 1993, it took over a decade to find the specimens…

“This is a great honor for me,” Debelius said.

Despite having several other marine creatures named after him, Debelius confessed he was excited to have a ’son’ in the seahorse family.

The five seahorses, described by science in December 2008 and January 2009 studies and all found in small ranges in the Red Sea and Indonesia, are the first to be discovered in five years.

Be sure to check out the other four gorgeous photos over in the National Geographic article.

Further reading:

1. Dracula fish species discovered in aquarium shipment
2. Blue Reef Aquarium breeds short-snouted seahorse
3. Histiophryne psychedelic: A crazy new fish species