Reef Ramblings

Starting From Scratch.

Hopefully, if you’ve decided to build your reef system from scratch you’ve been doing your homework and researching the animals you want to keep. With this research in mind you’ll now have a good idea of how to put your system together in light of the requirements of your chosen animals. Going this route will involve plenty of trips to your local aquatic shop to discuss the pros and cons of various manufacturers’ equipment. Most manufacturers of marine equipment will produce their own version of any product on the market, and of course each individual manufacturer will claim their version is the best!

So what constitutes a marine system?

At the very basic it’s a combination of the following items:

• Aquarium.
• Lighting.
• Water movement.
• Live substrate.
  

On top of this it’s usual to employ a Protein Skimmer, although many people are now resorting to what is often described as the more natural approach to the reef and using refugia or Miracle Mud systems either in addition or in place of the skimmer.

The Aquarium.

For marine aquaria, the proportions – length, breadth, height, and volume all have a significant part to play.

The larger the volume, the more stable the water conditions will be, and the greater the number of fish you’ll be able to keep, but, the larger the volume the more expensive it will be to fill with live rock and corals.

It’s a good thing to maximise the breadth of the tank, as this will reduce the foreshortening effect that you get in an aquarium, the appearance of all those rocks that make up your reef being squashed together. But do remember you still need to be able reach the back of the tank for maintenance.

Depth has a great significance on lighting. Due to the inverse square law, light reduces in inverse proportion to the square of the distance from its source, so the greater the depth of your tank, the greater amount of lighting you’re going to need. Again, this could reflect on the initial cost of your system plus day to day running costs.

Lighting.

Lighting is really dictated by the species of corals you want to keep plus the tank depth. There is no “best” lighting for the reef tank, only appropriate levels of lighting for the species being kept. Today we are seeing a trend to greater and greater amounts of light being used over reef aquaria but depending on your budget and choice of corals it’s not necessary to go for the ultimate in lighting.

We can split types of lighting for the reef into two categories, Metal Halide lighting and Fluorescent lighting. Fluorescent lighting can be further divided into T8 lamps, T5 lamps, and compact fluorescent or PL lamps.

Metal Halides remain my lighting of choice; as a point source they replicate the effect of the sun (also a point source) and as a result your reef will look more natural and alive, with shadows and glitter lines in evidence. You’re unlikely to get this effect from fluorescent lamps – a diffuse light source – unless you employ a great amount of surface water movement, even then you won’t get the shadows.

Drawbacks of MH lighting include initial expense, heat generation, and the necessity for them to be suspended over the tank.

Fluorescent lamps are perfectly adequate depending on species of corals kept.

T5s are probably the best bet, they are a smaller diameter tube than T8s hence there is less light lost due to the tube “self shading” itself beneath its reflector, plus these tubes have a higher output in terms of wattage compared to T8 tubes of equivalent length. T5s use energy efficient electronic ballasts and the tubes are claimed to have a longer useful life than T8s.

T8s have been the mainstay of the hobby for some years and many people have had great success using them on their reefs; I’ve maintained most species of corals under T8 lighting in the past including growing SPS corals. If it’s all you’ve got, use ‘em, otherwise unless you run electronic ballasts you’ll be better off with the T5s.

PLs are an odd one, they’ve been popular in the US for sometime but have only recently become generally available in the UK. They are in effect T5s that have been folded back on them selves to give the same wattage in half the length – think energy saver bulbs on steroids! You could get more wattage in a smaller space with these lamps but they do have the disadvantage of self-shading. I tend to favour these for use over refugia, they are often available as a tank top luminaire; it may be possible to get these at a lower price than T5s so they are still an option if you’re on a budget.

Most aquarists also employ what is termed dusk / dawn lighting. Usually a blue or actinic light, that will come on say an hour before the main lighting, remain on over the course of the day, then switch off about an hour after the main lighting. This helps avoid having a bright light suddenly coming on first thing in the morning and then last thing at night being abruptly plunged into darkness; conditions we want avoid as they can spook the fish into panicking or even jumping from the tank.

How many lamps do you need? As I said earlier, the amount of lighting required is really dependant upon the species of corals being kept.

As a starting point, I’d say that if you’re using MH lights then it’s one light for every 60cms(2ft) of tank length. You can quite successfully use a single light on a tank of up to 1 metre. Wattage, well that’s up to you, but do remember that with higher power outputs you’ll get a greater amount of heat and larger electricity bills!

Don’t use fluorescents on aquaria with a depth greater than 45cms(18ins). Use a minimum of four tubes on tanks of up to 38cms(15ins) breadth, for tanks over this add extra tubes as required. The wattage of a fluorescent tube is governed by its length, so go for the longest tubes that’ll fit the length of your aquarium.

LED Lighting.

At the time of writing LEDs are appearing on the market, the majority of them are inadequate and poorly designed, the exceptions tend to have a high price that doesn’t seem to be coming down in the near future. Avoid cheap Chinese junk and go for one of the high price units. They do the job of providing adequate light for coral growth and create superb glitter lines for very little energy cost. Unless LEDs are paired with fluorescent or HQI lighting the aquarium will appear very different to what you’re used to; it will not appear as bright even though adequate light is reaching the corals, the reason for this is that conventional lighting throws off indiscriminate glare in all directions (wasted light), which fools the eye into thinking, “Hey that’s bright”, whilst the LEDs use optics to direct all the light to where it’s required – the corals.

Water Movement.

As with lighting, there’s no “best” when it comes to amount of water flow, rather, what flow of water is most appropriate to the corals kept. And again, as with lighting, there has been a trend to higher and higher water flow. The easiest way to quantify water flow is in terms of tank turnover rate. Add together all the flow rates of the pumps used in the tank – e.g. if you have four Hydor Koralia 1 pumps, each rated at 1500l/h, that gives you a total of 6000l/h. Divide this figure by the volume of your tank in litres and you’ll have a number which tells you how many times an hour the water is turned over. E.g. 120cm x 60cms x 60 cms = 432l. 6000 ÷ 432 = 13.89. So we can say this set up has a turnover of around fourteen times an hour.

Up until recently this would have been considered a high turnover, but nowadays most people would consider this to be at the low end of the range. Look at starting with a turnover in the range of about 10 to 20 times an hour; this should be OK in a general or community reef tank.

In most cases water flow will be provided by the new generation of centrifugal pumps such as Koralias, as in the above example, rather than the more old-fashioned power head. At the very simplest you might just have a number of flow pumps of a size appropriate to your reef attached to the glass of the aquarium. By positioning them so that the flow from the pumps “interferes” with each other – directed at each other or by bouncing the flow off the glass – you can get some sort of chaotic flow going.

One problem with using multiple pumps inside the tank is that the heat generated by the pumps will be directly transferred to the water. By adding together the power consumption in watts of the pumps in question you’ll get an idea of the extra heat being added to the water. One increasingly popular way round this problem is to build what are termed Closed Loop Systems (CLS). This is where we use a fairly large, high flow pump outside of the aquarium, purely to produce flow. This is a system that can be used with most tanks and has the advantage that you don’t need to have a sump for it to work. By having the pump out of the water we can lose a proportion of the heat generated to the atmosphere, hence minimising heat build up within the tank.

Live Substrate.

Although the term live substrate can also be applied to sandbeds, and Mud systems, live rock is the form of live substrate that we’re primarily interested in.

Live Rock.

Live rock is at the heart of today’s reef aquarium and is the most important aspect of filtration. Unlike man-made biological filtration, which facilitates the nitrogen cycle by breaking ammonia down into nitrite, nitrite into nitrate – where it stops, leaving us with undesirable levels of nitrate which can fuel outbreaks of pest algae, live rock fully facilitates the nitrogen cycle, breaking down nitrate into harmless nitrogen gas.
Live rock is basically dead coral that has broken up over time due to the action of storms and, usefully for aquarists, it can be considered a natural, renewable resource. It tends to be highly porous and is thus capable of supporting large populations of bacteria, along with many other small organisms, such as algae, crustaceans, molluscs, sea squirts, sponges, worms, etc. Live rock introduces animals that help to turn the captive reef into a diverse, natural system, while its bacterial component is more than capable of processing the organic wastes produced by the larger inhabitants of the aquarium.

Ancillary Equipment.

Most reef tanks will also use a protein skimmer as part of the water processing equipment. Now a skimmer isn’t obligatory but, unless you’ve make your mind up to run a Miracle Mud system as a conscious decision to do without a skimmer, I’d thoroughly recommend using one to a beginner.

In my opinion one of the most useful aspects of the skimmer is that it is a form of filtration that can quickly adapt to an increase in load. So for your first reef where you’re learning all the time, if you have a problem, say an animal dies un-noticed, perhaps something living in the live rock that you’re unaware of, the skimmer is capable of reacting to the pollution and dealing with it without your intervention.

Mud systems originated with Miracle Mud from Ecosystems; the idea behind this is that by employing a bed of fine substrate and growing and harvesting macro-algae, such as Caulerpa species, you can achieve de-nitrification and the removal of potential pollutants which have become locked up in the algae you remove from the system.

Depending on the size of your system either of the above may be used as hang on items. For the larger system it’s usual to situate the skimmer or mud bed, in an ancillary tank, known as a sump, below the display aquarium.

Sumps are also a very useful way of getting the clutter of pumps and heaters out of the display tank. As this is part of a general book aimed at beginners, I think it would be out of place to go into the mechanics of building, plumbing, and setting up a sump. If you do want to utilise a sump, most good aquatic shops specialising in marines should be able to help you put together a sump system for your reef tank.

Tim Hayes

Midland Reefs

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