Saltwater Aquarium Advice

The process of lighting a saltwater aquarium serves two purposes; the first is to allow us to view the marine life and also to showcase and highlight the amazing colours that lie within. The second function is to mimic natural sunlight as closely as possible; to give our marine life some sort of day/night rhythm and provide food for the photosynthesising organisms such as corals, plants, coralline algae, phytoplankton and other invertebrates which use light as their energy source through photosynthesis. Ultimately this means they turn light and carbon dioxide into food (carbon), oxygen and water. The light requirement for this process is between 350- 750nm and is partly UVA.

To adequately light your marine aquarium the only 3 parameters you must consider are quality, quantity and duration of light.

Regular 12-16 hour lighting periods are optimal for good marine life health, a great idea is to use timers and have the actinic bulbs only on for 1-2 hours each end to simulate dawn and dusk.

The best lighting system will be a combination of actinic (blue) and daylight bulbs.

As a general rule of thumb the bulbs needed to sustain photosynthetic light should have a colour temperature of around 6500°K - 12000°K for general reef applications (colour temperature increases with depth so much deeper water species require higher colour temperatures, these are very specialist). You should also aim for 3 (soft corals) to 5 (hard corals) watts of light per gallon of saltwater as another general rule, this will help you decide how many bulbs at what wattage you will need.

Optimal lighting is a delicate arrangement that is dictated by the type of saltwater aquarium you plan to keep and what creatures you plan to keep in it. Photosynthesising marine life falls into 3 different catergories: low light species such as large polyped stony corals (LPS), moderate light species such as many soft corals and high light loving including many small polyped stony corals (SPS) and Tridacnid clams.

The trick here is to try and get compatible species that thrive under similar light conditions or get very creative at placing high light species higher up towards the lights and moderate light species lower in the aquarium this way you wont saturate some species with too much light (damaging) or cause some species to not receive enough lighting for good growth. Species that are not getting as much light as they should be can to some degree be compensated with supplementary feeding such as plankton.

The most simplistic lighting requirements can be used for fish only aquariums where all you want to do is be able to view your fish and give them a day/night cycle. Fluorescent lights of normal/standard output (NO) are all that is required here; full spectrum bulbs produce a more natural looking light and actinic blue lights bring out colourful pigments nicely.

Fish Only with Live Rock (FOWLR) aquariums typically include the photosynthesising coralline algae encrusting the live rock and a handful of select invertebrates, depending on how many and which type of corals and/or photosynthetic anemones you have you may want to go up to high output fluorescents (greater luminosity than normal output fluoros) such as a T5 set up. T5 lights have become extremely popular in the past few years. If combined with electronic ballast they run cooler, longer and more energy efficiently than other lighting set ups, they also penetrate the water better than many other types of thicker bulbs.

If you have little more than Live rock in your FOWLR simple actinic blue fluorescents will suffice to keep the photosynthetic creatures and algae happy and thus increase water quality too.

As you may have guessed by now a reef aquarium requires the most intensive lighting set up and to a reef lighting is as important for good health as filtration. Often times lighting will be one of the most expensive components in a reef aquarium.  I recommend HO fluorescents (such as T5’s) to VHO (very high output) fluorescents for deeper, larger aquariums or more sensitive species, with a combination of actinic blue and daylight bulbs. Many aquarists use metal halide lights but because of their expense, excessive heat output, high UV radiation (use shields here), high electricity usage and limited lighting penetration over fluorescents I don’t really see the real advantage of the additional costs involved.

Retrofit systems and other fluorescent lamp housings should have the light bulbs no more than 3 inches above the water surface. Reflectors should be used to direct light to the water, many bulbs no have reflectors built in, these are very efficient.

When choosing a lighting set up other than knowing what marine life you plan to keep you should always take into consideration the initial cost of the system, the operating costs (electricity), bulb replacement costs (and frequency of replacement), whether or not you would need a chiller for the aquarium and the ease and eventual need for any upgrading. Some systems maybe cheaper initially but may require more frequent bulb changes or chilling systems because of heat generated making them more expensive in the long run.

As an avid marine aquarist, I have watched over the years as reef aquariums grow massively in popularity.  These days nano reefs and pico reefs are very popular as people are drawn toward smaller size (and perceived lower cost) of these tiny reef set ups. Typically nano reefs are less than 30 gallons (140L) in volume and pico reefs are super tiny at 5 gallons or less.

A reef aquarium is defined as a marine aquarium with the focus on corals and invertebrates rather than fish.  The key component of a reef aquarium is live rock used to “landscape” the tank and also as a primary mean of biological filtration.  As reef aquariums focus on the corals and other marine invertebrates the aim here is to truly make them look as if a slab of the native reef has been removed from the ocean and is now growing in your own home! Its also really fun to set up biotope reefs, for example I have done a Pacific island reef set up and seen another Caribbean one done.

One thing about reef aquariums versus fish-only or fish and live rock (FOWLR) is that water quality and vigorous water movement become much more of a must have here because of the corals requirements to thrive. Additionally, marine creature selection becomes a lot more important in reef set ups because of compatibility issues with fish, corals and other marine invertebrates making the situation a lot more difficult to balance. If you dont know what you are doing you can easily make expensive mistakes here, check out my best selling ebook “Ultimate Secrets to Saltwater Aquarium Fish and Invertebrates” for easy steps to selecting marine species correctly the first time and everything else you could possibly want to knowing about owning a thriving reef aquarium.

Lighting is a major component of a good reef aquarium set up, this is so important because of the corals ability to photosynthesize to produce their food, Therefore the conditions of the tropical sun in real reef habitats will need to be effectively mimicked.  The most common lighting choices for reefers are: metal halide, T5, compact fluorescent or VHO (very high output) bulbs. Most reefers aim for 5-8 watts of light ouput per gallon of water. The key to a thriving reef environment is to choose your lighting to complement the requirements of the corals you want, then place the corals in the aquarium in their preferred proximity to the lights in the water column and in the appropriate water turbulence region. This may sound easier said than done but a little research and careful planning on you part will make the difference between a spectacular reef and a failure.

Never underestimate the water movement conditions your corals require. Water movement is vital to corals because it brings them their food (when the lights are off the coral polyps begin snatching plankton from the water, no coral relies solely on photosynthesis and some are entirely carnivorous), enables corals to respirate (brings O2 and takes away CO2), keeps them cool (important under hot lights), assists them in shedding protective tissue and finally rinses detritus and debris from the coral that would otherwise rot and potentially cause infection. Water movement can be easily regulated with the clever use of powerheads.

So, even though reef tanks sound complex believe me when I say they are extremely rewarding. A little careful research, planning and preparation on your part can result in a stunning reef that will be your pride and joy for years to come.